lkml.org 
[lkml]   [2023]   [Sep]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/3] platform/x86: intel_scu_ipc: Check status upon timeout in ipc_wait_for_interrupt()
On Wed, Aug 30, 2023 at 06:14:02PM -0700, Stephen Boyd wrote:
> It's possible for the completion in ipc_wait_for_interrupt() to timeout,
> simply because the interrupt was delayed in being processed. A timeout
> in itself is not an error. This driver should check the status register
> upon a timeout to ensure that scheduling or interrupt processing delays
> don't affect the outcome of the IPC return value.
>
> CPU0 SCU
> ---- ---
> ipc_wait_for_interrupt()
> wait_for_completion_timeout(&scu->cmd_complete)
> [TIMEOUT] status[IPC_BUSY]=0
>
> Fix this problem by reading the status bit in all cases, regardless of
> the timeout. If the completion times out, we'll assume the problem was
> that the IPC_BUSY bit was still set, but if the status bit is cleared in
> the meantime we know that we hit some scheduling delay and we should
> just check the error bit.
>
> Cc: Prashant Malani <pmalani@chromium.org>
> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

\
 
 \ /
  Last update: 2023-09-01 08:05    [W:0.116 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site