So we can de-duplicate code that's inside intel_dp_start_link_train
and intel_dp_complete_link_train.
V2: Rebase since patch 3/5 was discarded.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
As the stolen memory region will contain the contents of whatever was
last there, it invariably contains garbage. To be consistent with the
shmemfs backed fb and the expectations of the fb layer, we need to clear
the fb prior to installing it as an fbcon.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=58111
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Fixup sparse __iomem confusion reported by Wu Fengguang.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Only the intel_crtc->active is accurate at the point where we wish to
perform WM computations, so use it instead of crtc->enabled.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
If we elect to disable self-refresh as they require too many FIFO
entries, clear the values prior to writing them into the registers. If
they are too large they may occupy more bits than available and so
corrupt neighbouring WM values.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We ignore all the user requests to handle flushing to the GTT domain if
the user requests such on a snoopable bo, and as such access through the
GTT to such pages remains incoherent. The specs even warn that such
behaviour is undefined - a strong reason never to do so.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Daniel writes:
A few leftover fixes for 3.8:
- VIC support for hdmi infoframes with the associated drm helper, fixes
some black TVs (Paulo Zanoni)
- Modeset state check (and fixup if the BIOS messed with the hw) for
lid-open. modeset-rework fallout. Somehow the original reporter went
awol, so this stalled for way too long until we've found a new
victim^Wreporter with broken BIOS.
- seqno wrap fixes from Mika and Chris.
- Some minor fixes all over from various people.
- Another race fix in the pageflip vs. unpin code from Chris.
- hsw vga resume support and a few more fdi link fixes (only used for vga
on hsw) from Paulo.
- Regression fix for DMAR from Zhenyu Wang - I've scavenged memory from my
DMAR for a while and it broke right away :(
- Regression fix from Takashi Iwai for ivb lvds - some w/a needs to be
(partially) moved back into place. Note that these are regressions in
-next.
- One more fix for ivb 3 pipe support - it now actually seems to work.
* 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel: (25 commits)
drm/i915: Fix missed needs_dmar setting
drm/i915: Fix shifted screen on top of LVDS on IVY laptop
drm/i915: disable cpt phase pointer fdi rx workaround
drm/i915: set the LPT FDI RX polarity reversal bit when needed
drm/i915: add lpt_init_pch_refclk
drm/i915: add support for mPHY destination on intel_sbi_{read, write}
drm/i915: reject modes the LPT FDI receiver can't handle
drm/i915: fix hsw_fdi_link_train "retry" code
drm/i915: Close race between processing unpin task and queueing the flip
drm/i915: fixup l3 parity sysfs access check
drm/i915: Clear the existing watermarks for g4x when modifying the cursor sr
drm/i915: do not access BLC_PWM_CTL2 on pre-gen4 hardware
drm/i915: Don't allow ring tail to reach the same cacheline as head
drm/i915: Decouple the object from the unbound list before freeing pages
drm/i915: Set sync_seqno properly after seqno wrap
drm/i915: Include the last semaphore sync point in the error-state
drm/i915: Rearrange code to only have a single method for waiting upon the ring
drm/i915: Simplify flushing activity on the ring
drm/i915: Preallocate next seqno before touching the ring
drm/i915: force restore on lid open
...
The function doesn't use any of the registers mentioned, nor does it
return true or false. Hard to do worse. Remove it, the function is
absolutely descriptive enough to not need any comment.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
CPT+ PCHs have different bit definition to read the HPD live status. I
don't have an ILK with digital ports handy, which is why this patch is
separate from the CPT+ implementation. If the docs don't lie, it should
all be fine though.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Moving the DPCD just after a successful read will allow to:
- log all DPCD reads (eDP ones, changes signalled by HPD IRQ)
- don't log it if we haven't been able to read it
v2: Be sure to log the DPCD when a downstream port does not have HPD
support and the branch device asserts HPD (Jani Nikula)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Just like:
Author: Damien Lespiau <damien.lespiau@intel.com>
Date: Wed Dec 12 19:37:22 2012 +0000
drm/i915/hdmi: Read the HPD status before trying to read the EDID
But this time for DiplayPort.
v2: Adapt to the ibx_ name change and don't add commit hash (Chris
Wilson, Jani Nikula)
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
If you unplug the hdmi connector slowly enough, the hotplug interrupt
fires but then the kernel code tries to read the EDID and succeeds
(because the connector is still half connected, the HPD pin is shorter
than the others, and DDC works). Since EDID succeeds it thinks the
monitor is still connected.
To prevent that, read the live HPD status in the hotplug handler before
trying to read the EDID.
v2: Rename the function to ibx_ (Chris Wilson)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=55372
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Those status bits don't follow the usual pattern: _MASK (those bits are
write 1 to clear, useful to select the value we want to read) and the
values shifted by the same amount.
Cleaned that that up when poking at the register for testing purposes,
might as well upstream that cleanup.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From Ben's AGP dependence removal change, "needs_dmar" flag has not
been properly setup for new chips using new GTT init function. This
one adds missed setting of that flag to make sure we do pci mappings
with IOMMU enabled.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Spinning for up to 200 us with interrupts locked out is not good. So
let's just spin (and even that seems to be excessive).
And we don't call these functions from interrupt context, so this is
not required. Besides that doing anything in interrupt contexts which
might take a few hundred us is a no-go. So just convert the entire
thing to a mutex. Also move the mutex-grabbing out of the read/write
functions (add a WARN_ON(!is_locked)) instead) since all callers are
nicely grouped together.
Finally the real motivation for this change: Dont grab the modeset
mutex in the dpio debugfs file, we don't need that consistency. And
correctness of the dpio interface is ensured with the dpio_lock.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
For GMCH platforms we set up the hpd irq registers in the irq
postinstall hook. But since we only enable the irq sources we actually
need in PORT_HOTPLUG_EN/STATUS, taking dev_priv->hotplug_supported_mask
into account, no hpd interrupt sources is enabled since
commit 52d7ecedac
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat Dec 1 21:03:22 2012 +0100
drm/i915: reorder setup sequence to have irqs for output setup
Wrongly set-up interrupts also lead to broken hw-based load-detection
on at least GM45, resulting in ghost VGA/TV-out outputs.
To fix this, delay the hotplug register setup until after all outputs
are set up, by moving it into a new dev_priv->display.hpd_irq_callback.
We might also move the PCH_SPLIT platforms to such a setup eventually.
Another funny part is that we need to delay the fbdev initial config
probing until after the hpd regs are setup, for otherwise it'll detect
ghost outputs. But we can only enable the hpd interrupt handling
itself (and the output polling) _after_ that initial scan, due to
massive locking brain-damage in the fbdev setup code. Add a big
comment to explain this cute little dragon lair.
v2: Encapsulate all the fbdev handling by wrapping the move call into
intel_fbdev_initial_config in intel_fb.c. Requested by Chris Wilson.
v3: Applied bikeshed from Jesse Barnes.
v4: Imre Deak noticed that we also need to call intel_hpd_init after
the drm_irqinstall calls in the gpu reset and resume paths - otherwise
hotplug will be broken. Also improve the comment a bit about why
hpd_init needs to be called before we set up the initial fbdev config.
Bugzilla: Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=54943
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v3)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
To gain confidence in the wrap handling, make it happen quite
soon after the boot.
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The complication is that during seqno wrapping we must be extremely
careful not to write to any ring as that will require a new seqno, and
so would recurse back into the seqno wrap handler. So we cannot call
i915_gpu_idle() as that does additional work beyond simply retiring the
current set of requests, and instead must do the minimal work ourselves
during seqno wrapping.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
If wrap just happened we need to prevent emitting waits for
pre wrap values. Detect this and emit no-ops instead.
v2: Use olr > seqno to detect wrap instead of *seqno == 0
as suggested by Chris Wilson.
v3: Use last used seqno to detect the wraparound. From
Chris Wilson
v4: Fixed unnecessary last_seqno assigment
References: https://bugs.freedesktop.org/show_bug.cgi?id=57967
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The commit [23670b322: drm/i915: CPT+ pch transcoder workaround]
caused a regression on some HP laptops with IvyBridge. The whole
laptop screen is shifted downward for a few pixels constantly.
The problem appears only on LVDS while DP and VGA seem unaffected.
Also, the problem disappears once when go and back from S3.
(S4 resume still shows the same problem.)
This patch revives the minimum part the commit above dropped.
For fixing this regression, only the setup of CHICKEN2 bit in
cpt_init_clock_gating() is needed.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We've originally added this in
commit 291427f5fd
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Fri Jul 29 12:42:37 2011 -0700
drm/i915: apply phase pointer override on SNB+ too
and then copy-pasted it over to ivb/ppt. The w/a was originally added
for ilk/ibx in
commit 5b2adf8971
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Thu Oct 7 16:01:15 2010 -0700
drm/i915: add Ironlake clock gating workaround for FDI link training
and fixed up a bit in
commit 6f06ce184c
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Tue Jan 4 15:09:38 2011 -0800
drm/i915: set phase sync pointer override enable before setting phase sync pointer
It turns out that this w/a isn't actually required on cpt/ppt and
positively harmful on ivb/ppt when using fdi B/C links - it results in
a black screen occasionally, with seemingfully everything working as
it should. The only failure indication I've found in the hw is that
eventually (but not right after the modeset completes) a pipe underrun
is signalled.
Big thanks to Arthur Runyan for all the ideas for registers to check
and changes to test, otherwise I couldn't ever have tracked this down!
Cc: "Runyan, Arthur J" <arthur.j.runyan@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This reverts commits a50915394f and
d7c3b937bd.
This is a revert of a revert of a revert. In addition, it reverts the
even older i915 change to stop using the __GFP_NO_KSWAPD flag due to the
original commits in linux-next.
It turns out that the original patch really was bogus, and that the
original revert was the correct thing to do after all. We thought we
had fixed the problem, and then reverted the revert, but the problem
really is fundamental: waking up kswapd simply isn't the right thing to
do, and direct reclaim sometimes simply _is_ the right thing to do.
When certain allocations fail, we simply should try some direct reclaim,
and if that fails, fail the allocation. That's the right thing to do
for THP allocations, which can easily fail, and the GPU allocations want
to do that too.
So starting kswapd is sometimes simply wrong, and removing the flag that
said "don't start kswapd" was a mistake. Let's hope we never revisit
this mistake again - and certainly not this many times ;)
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we fail to set the bit when needed we get some nice FDI link
training failures (AKA "black screen on VGA output").
While we don't really know how to properly choose whether we need to
set the bit or not (VBT?), just read the initial value set by the BIOS
and store it for later usage.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We need this code to init the PCH SSC refclk and the FDI registers.
The BIOS does this too and that's why VGA worked before this patch,
until you tried to suspend the machine...
This patch implements the "Sequence to enable CLKOUT_DP for FDI usage
and configure PCH FDI/IO" from our documentation.
v2:
- Squash Damien Lespiau's reset spelling fix on top.
- Add a comment that we don't need to bother about the ULT special
case Damien noticed, since ULT won't have VGA.
- Add a comment to rip out the SDV codepaths once haswell ships for
real.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Alex writes:
Pretty minor -next pull request. We some additional new bits waiting
internally for release. Hopefully Monday we can get at least some of
them out. The others will probably take a few more weeks.
Highlights of the current request:
- ELD registers for passing audio information to the sound hardware
- Handle GPUVM page faults more gracefully
- Misc fixes
Merge radeon test
* 'drm-next-3.8' of git://people.freedesktop.org/~agd5f/linux: (483 commits)
drm/radeon: bump driver version for new info ioctl requests
drm/radeon: fix eDP clk and lane setup for scaled modes
drm/radeon: add new INFO ioctl requests
drm/radeon/dce32+: use fractional fb dividers for high clocks
drm/radeon: use cached memory when evicting for vram on non agp
drm/radeon: add a CS flag END_OF_FRAME
drm/radeon: stop page faults from hanging the system (v2)
drm/radeon/dce4/5: add registers for ELD handling
drm/radeon/dce3.2: add registers for ELD handling
radeon: fix pll/ctrc mapping on dce2 and dce3 hardware
Linux 3.7-rc7
powerpc/eeh: Do not invalidate PE properly
Revert "drm/i915: enable rc6 on ilk again"
ALSA: hda - Fix build without CONFIG_PM
of/address: sparc: Declare of_iomap as an extern function for sparc again
PM / QoS: fix wrong error-checking condition
bnx2x: remove redundant warning log
vxlan: fix command usage in its doc
8139cp: revert "set ring address before enabling receiver"
MPI: Fix compilation on MIPS with GCC 4.4 and newer
...
Conflicts:
drivers/gpu/drm/exynos/exynos_drm_encoder.c
drivers/gpu/drm/exynos/exynos_drm_fbdev.c
drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
This way we should be able to write mPHY registers using the Sideband
Interface in the next commit. Also fixed some syntax oddities in the
related code.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
smatch warning:
drivers/gpu/drm/i915/intel_display.c:7019 intel_set_mode() warn: function puts
500 bytes on stack
Refactor so that saved_mode and saved_hwmode are dynamically allocated as opposed
to being automatic variables. 500 bytes seems like it could run the potential for blowing
the kernel stack.
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Commit 9ee32fea5f unconditionally prevents the CPU from entering idle states
until intel_dp_aux_ch completes for the first time, which never happens on my
DisplayPort-less intel gfx, causing the CPU to get rather hot.
Signed-off-by: Tomas Janousek <tomi@nomi.cz>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
More specifically, the LPT FDI RX only supports 8bpc and a maximum of
2 lanes, so anything above that won't work and should be rejected.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We were previously doing exactly what the "mode set sequence for CRT"
document mandates, but whenever we failed to train the link in the
first tentative, all the other subsequent retries always failed. In
one of my monitors that has 47 modes, I was usually getting around 3
failures when running "testdisplay -a".
After this patch, even if we fail in the first tentative, we can
succeed in the next ones. So now when running "testdisplay -a" I see
around 3 times the message "FDI link training done on step 1" and no
failures.
Notice that now the "retry" code looks a lot like the DP retry code.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
On a machine with bit17 swizzling, we need to store the bit17 of the
physical page address in put-pages. This requires a memory allocation,
on average less than a page, which may be difficult to satisfy is the
request to put-pages is on behalf of the shrinker. We could allow that
allocation to pull from the reserved memory pools, but it seems much
safer to preallocate the array for tiled objects on affected machines.
v2: Export i915_gem_object_needs_bit17_swizzle() for reuse.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Both the dp and fdi code use the exact same computations (ignore minor
differences in conversion between bits and bytes).
This makes it even more apparent that we have a _massive_ mess between
cpu transcoder/fdi link/pch transcoder and pch link settings. And also
that we have hilarious amounts of confusion between edp and dp
(despite that they're identical at a link level).
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This has originally been added in
commit 8db9d77b1b
Author: Zhenyu Wang <zhenyuw@linux.intel.com>
Date: Wed Apr 7 16:15:54 2010 +0800
drm/i915: Support for Cougarpoint PCH display pipeline
probably to combat issues with hw state left behind by the BIOS. And
indeed, I've checked out that specific revision, and there is no DP
support yet. So the pch dp transcoder won't be correctly disabled, and
that's important since it requires a rether special disable dance:
Just writing 0 to TRANS_DP_CTL won't cut it, since we need to select
the NONE port when disabling, too.
And indeed, things seem to still work, so let's just remove this.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This could have happened with the old crtc helper based modeset code,
but can't happen any longer with the new code.
Hence put in a WARN and adjust the comment. If no one hits this, we
can eventually remove it (like a few other such cases across our
code).
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
17 ms is eerily close to 60 Hz ^-1
Unfortunately this goes back to the original DP enabling for ilk, and
unfortunately does not come with a reason for it's existance attached.
Some closer inspection of the code and DP specs shows that we set the
idle link pattern before we disable the port. And it seems like that
the DP spec (or at least our hw) only switch to the idle pattern on
the next vblank. Hence a vblank wait at this spot makes _much_ more
sense than a really long wait.
v2: Rebase fixup.
v3: Add comment requested by Paulo Zanoni saying that we don't really
know what this wait is for.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
While reading docs I've noticed that this special workaround to select
the 1.6 GHz DP clock only applies to pre-production ilk machines.
Since the registers we're touching here are rather undocumented and
might be harmful on later chips, rip it out.
For the Bspec reference of this w/a look in "vol4g CPU Display
Registers [DevILK]", Section 4.1.7.1 "DP_A—DisplayPort A
Control Register", "DP_PLL_Frequency_Select".
v2: Keep a debug message as a hint in case something regresses.
Requested by Chris Wilson.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now that we enable the cpu edp pll in intel_dp->pre_enable and no
longer in crtc_mode_set, we can also move the modeset part to the
intel_dp->mode_set callback. Previously this was not possible because
the encoder ->mode_set callbacks are called after the crtc mode set
callback.
v2: Rebase on top of copy&pasted hsw crtc_mode_set.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Especially getting rid of all things lvds is ... great!
v2: Drop the two additional pre-hsw hunks noticed by Paulo Zanoni.
v3:
- handle DP ports correctly (spoted by Paulo)
- don't leave {} behind for a single-line block (again spotted by
Paulo)
- kill another if (IBX || CPT) block
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Before queuing the flip but crucially after attaching the unpin-work to
the crtc, we continue to setup the unpin-work. However, should the
hardware fire early, we see the connected unpin-work and queue the task.
The task then promptly runs and unpins the fb before we finish taking
the required references or even pinning it... Havoc.
To close the race, we use the flip-pending atomic to indicate when the
flip is finally setup and enqueued. So during the flip-done processing,
we can check more accurately whether the flip was expected.
v2: Add the appropriate mb() to ensure that the writes to the page-flip
worker are complete prior to marking it active and emitting the MI_FLIP.
On the read side, the mb should be enforced by the spinlocks.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
[danvet: Review the barriers a bit, we need a write barrier both
before and after updating ->pending. Similarly we need a read barrier
in the interrupt handler both before and after reading ->pending. With
well-ordered irqs only one barrier in each place should be required,
but since this patch explicitly sets out to combat spurious interrupts
with is staged activation of the unpin work we need to go full-bore on
the barriers, too. Discussed with Chris Wilson on irc and changes
acked by him.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Less clutter in the traces. And in both cases we yell rather loud
into the logs if we time out. Patch suggested by Chris Wilson.
v2: Annotate another I915_READ in dp_aux to be consistent - we filter
out all register io in wait_for and similar loops. Chris also
suggested to mark all dp_aux register access as _NOTRACE, but I think
we should keep all functionally relevant access around, and filter
unneeded bits in userspace after the trace is captured.
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
At least on the platforms that have a dp aux irq and also have it
enabled - vlvhsw should have one, too. But I don't have a machine to
test this on. Judging from docs there's no dp aux interrupt for gm45.
Also, I only have an ivb cpu edp machine, so the dp aux A code for
snb/ilk is untested.
For dpcd probing when nothing is connected it slashes about 5ms of cpu
time (cpu time is now negligible), which agrees with 3 * 5 400 usec
timeouts.
A previous version of this patch increases the time required to go
through the dp_detect cycle (which includes reading the edid) from
around 33 ms to around 40 ms. Experiments indicated that this is
purely due to the irq latency - the hw doesn't allow us to queue up
dp aux transactions and hence irq latency directly affects throughput.
gmbus is much better, there we have a 8 byte buffer, and we get the
irq once another 4 bytes can be queued up.
But by using the pm_qos interface to request the lowest possible cpu
wake-up latency this slowdown completely disappeared.
Since all our output detection logic is single-threaded with the
mode_config mutex right now anyway, I've decide not ot play fancy and
to just reuse the gmbus wait queue. But this would definitely prep the
way to run dp detection on different ports in parallel
v2: Add a timeout for dp aux transfers when using interrupts - the hw
_does_ prevent this with the hw-based 400 usec timeout, but if the
irq somehow doesn't arrive we're screwed. Lesson learned while
developing this ;-)
v3: While at it also convert the busy-loop to wait_for_atomic, so that
we don't run the risk of an infinite loop any more.
v4: Ensure we have the smallest possible irq latency by using the
pm_qos interface.
v5: Add a comment to the code to explain why we frob pm_qos. Suggested
by Chris Wilson.
v6: Disable dp irq for vlv, that's easier than trying to get at docs
and hw.
v7: Squash in a fix for Haswell that Paulo Zanoni tracked down - the
dp aux registers aren't at a fixed offset any more, but can be on the
PCH while the DP port is on the cpu die.
Reviewed-by: Imre Deak <imre.deak@intel.com> (v6)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
GMBUS_ACTIVE has inverted sense and so doesn't fit into the
wait_hw_status helper, hence create a new gmbus_wait_idle functions.
Also, we only care about the idle irq event and nothing else, which
allows us to use the wait_event_timeout helper directly without
jumping through hoops to catch NAKs.
Since gen2/3 don't have gmbus interrupts, handle them separately with
the old wait_for macro.
This shaves another few ms off reading EDID from a hdmi screen on my
testbox here. EDID reading with interrupt driven gmbus is now as fast
as with busy-looping gmbus at 28 ms here (with negligible cpu
overhead).
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We need two special things to properly wire this up:
- Add another argument to gmbus_wait_hw_status to pass in the
correct interrupt bit in gmbus4.
- Since we can only get an irq for one of the two events we want,
hand-roll the wait_event_timeout code so that we wake up every
jiffie and can check for NAKs. This way we also subsume gmbus
support for platforms without interrupts (or where those are not
yet enabled).
The important bit really is to only enable one gmbus interrupt source
at the same time - with that piece of lore figured out, this seems to
work flawlessly.
Ben Widawsky rightfully complained the lack of measurements for the
claimed benefits (especially since the first version was actually
broken and fell back to bit-banging). Previously reading the 256 byte
hdmi EDID takes about 72 ms here. With this patch it's down to 33 ms.
Given that transfering the 256 bytes over i2c at wire speed takes
20.5ms alone, the reduction in additional overhead is rather nice.
v2: Chris Wilson wondered whether GMBUS4 might contain some set bits
when booting up an hence result in some spurious interrupts. Since we
clear GMBUS4 after every wait and we do gmbus transfer really early in
the setup sequence to detect displays the window is small, but still
be paranoid and clear it properly.
v3: Clarify the comment that gmbus irq generation can only support one
kind of event, why it bothers us and how we work around that limit.
Cc: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
