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ARM: PL08x: fix locking between prepare function and submit function

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The PL08x driver holds on to the channel lock with interrupts disabled
between the prepare and the subsequent submit API functions.  This
means that the locking state when the prepare function returns is
dependent on whether it suceeeds or not.

It did this to ensure that the physical channel wasn't released, and
as it used to add the descriptor onto the pending list at prepare time
rather than submit time.

Now that we have reorganized the code to remove those reasons, we can
now safely release the spinlock at the end of preparation and reacquire
it in our submit function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Russell King - ARM Linux
2011-01-03 22:45:37 +00:00
committed by Dan Williams
parent 8087aacda0
commit c370e594ef
2 changed files with 9 additions and 23 deletions
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4
include/linux/amba/pl08x.h
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@@ -162,9 +162,6 @@ enum pl08x_dma_chan_state {
* @lc: last completed transaction on this channel
* @pend_list: queued transactions pending on this channel
* @at: active transaction on this channel
* @lockflags: sometimes we let a lock last between two function calls,
* especially prep/submit, and then we need to store the IRQ flags
* in the channel state, here
* @lock: a lock for this channel data
* @host: a pointer to the host (internal use)
* @state: whether the channel is idle, paused, running etc
@@ -184,7 +181,6 @@ struct pl08x_dma_chan {
dma_cookie_t lc;
struct list_head pend_list;
struct pl08x_txd *at;
unsigned long lockflags;
spinlock_t lock;
struct pl08x_driver_data *host;
enum pl08x_dma_chan_state state;