From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Stephen Boyd <swboyd@chromium.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
Hans de Goede <hdegoede@redhat.com>,
Mark Gross <markgross@kernel.org>,
linux-kernel@vger.kernel.org, patches@lists.linux.dev,
platform-driver-x86@vger.kernel.org,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Prashant Malani <pmalani@chromium.org>
Subject: Re: [PATCH 1/3] platform/x86: intel_scu_ipc: Check status after timeouts in busy_loop()
Date: Thu, 31 Aug 2023 16:53:14 +0300 [thread overview]
Message-ID: <ZPCbSse3J6ksZwJa@smile.fi.intel.com> (raw)
In-Reply-To: <20230831011405.3246849-2-swboyd@chromium.org>
On Wed, Aug 30, 2023 at 06:14:01PM -0700, Stephen Boyd wrote:
> It's possible for the polling loop in busy_loop() to get scheduled away
> for a long time.
>
> status = ipc_read_status(scu);
> <long time scheduled away>
> if (!(status & IPC_STATUS_BUSY))
>
> If this happens, then the status bit could change and this function
> would never test it again after checking the jiffies against the timeout
> limit. Polling code should check the condition one more time after the
> timeout in case this happens.
>
> The read_poll_timeout() helper implements this logic, and is shorter, so
> simply use that helper here.
I don't remember by heart, but on some older Intel hardware this might have
been called during early stages where ktime() is not functional yet.
Is this still a case here?
...
Codewise change looks good to me.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2023-08-31 14:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-31 1:14 [PATCH 0/3] platform/x86: intel_scu_ipc: Timeout fixes Stephen Boyd
2023-08-31 1:14 ` [PATCH 1/3] platform/x86: intel_scu_ipc: Check status after timeouts in busy_loop() Stephen Boyd
2023-08-31 13:53 ` Andy Shevchenko [this message]
2023-09-05 22:24 ` Stephen Boyd
2023-09-06 13:58 ` Andy Shevchenko
2023-08-31 14:15 ` Kuppuswamy Sathyanarayanan
2023-09-01 5:50 ` Mika Westerberg
2023-09-05 22:27 ` Stephen Boyd
2023-09-06 13:46 ` Andy Shevchenko
2023-09-06 14:31 ` Mika Westerberg
2023-08-31 1:14 ` [PATCH 2/3] platform/x86: intel_scu_ipc: Check status upon timeout in ipc_wait_for_interrupt() Stephen Boyd
2023-08-31 13:58 ` Andy Shevchenko
2023-09-05 22:36 ` Stephen Boyd
2023-08-31 14:27 ` Kuppuswamy Sathyanarayanan
2023-09-05 22:56 ` Stephen Boyd
2023-09-01 6:04 ` Mika Westerberg
2023-08-31 1:14 ` [PATCH 3/3] platform/x86: intel_scu_ipc: Fail IPC send if still busy Stephen Boyd
2023-08-31 14:07 ` Andy Shevchenko
2023-09-01 6:06 ` Mika Westerberg
2023-09-05 22:42 ` Stephen Boyd
2023-08-31 3:28 ` [PATCH 0/3] platform/x86: intel_scu_ipc: Timeout fixes Kuppuswamy Sathyanarayanan
2023-09-05 22:55 ` Stephen Boyd
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