The rules used to make 8250_pci "ignore" the PCH uarts are lacking pci subids
entries, preventing it to match and thus is breaking serial port support for
theses systems.
This has been tested on a nanoETXexpress-TT, which has a specifici uart clock.
Tested-by: Erwan Velu <Erwan.Velu@zodiacaerospace.com>
[stable@: please apply to 3.0-stable, 3.2-stable and 3.3-stable]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Arnaud Patard <apatard@hupstream.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using Serial Over Lan (SOL) over the virtual serial port in a Intel
management engine (ME) device, on device reset the serial FIFOs need to
be cleared to keep the FIFO indexes in-sync between the host and the
engine.
On a reset the serial device assertes BI, so using that as a cue FIFOs
are cleared. So for this purpose a new handle_break callback has been
added. One other problem is that the serial registers might temporarily
go to 0 on reset of this device. So instead of using the IER register
read, if 0 returned use the ier value in uart_8250_port. This is hidden
under a custom serial_in.
Cc: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Workaround dropped notifications in the iir register. Register reads
coincident with new interrupt notifications sometimes result in this
device clearing the interrupt event without reporting it in the read
data.
The serial core already has a heuristic for determining when a device
has an untrustworthy iir register. In this case when we apriori know
that the iir is faulty use a flag (UPF_BUG_THRE) to bypass the test and
force usage of the background timer.
[stable: 3.3.x]
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Reported-by: Nhan H Mai <nhan.h.mai@intel.com>
Reported-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Tested-by: Nhan H Mai <nhan.h.mai@intel.com>
Tested-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 448ac154c9.
The semantic of UPF_IIR_ONCE is only guaranteed to workaround the race
condition in the kt serial's iir register if the only source of
interrupts is THRE (fifo-empty) events. An modem status event at the
wrong time can again cause an iir read to drop the 'empty' status
leading to a hang. So, revert this in preparation for using the
existing "I don't trust my iir register" workaround in the 8250 core
(UART_BUG_THRE).
[stable: 3.3.x]
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Sudhakar Mamillapalli <sudhakar@fb.com>
Reported-by: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit e86ff4a63c.
This tried to enforce the semantics of one interrupt per iir read of the
THRE (transmit-hold empty) status, but events from other sources
(particularly modem status) defeat this guarantee.
This change also broke 8250_pci suspend/resume support as
pciserial_resume_ports() re-runs .init() quirks, but does not run
.exit() quirks in pciserial_suspend_ports() leading to reports like:
sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:16.3/msi_irqs'
...and a subsequent crash. The mismatch of init/exit at suspend/resume
seems like a bug in its own right.
[stable: 3.3.x]
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: Sudhakar Mamillapalli <sudhakar@fb.com>
Reported-by: Nhan H Mai <nhan.h.mai@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The drivers/tty/serial dir is already getting rather busy.
Relocate the 8250 related drivers to their own subdir to
reduce the clutter.
Note that sunsu.c is not included in this move -- it is
8250-like hardware, but it does not use any of the existing
infrastructure -- and does not depend on SERIAL_8250.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
