Re: [PATCH 03/25] media: venus: Rework error fail recover logic
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Date: 2021-05-05 11:06:49
Also in:
linux-arm-msm, lkml
On Wed, 5 May 2021 11:41:53 +0200 Mauro Carvalho Chehab [off-list ref] wrote:
The Venus code has a sort of watchdog that attempts to recover
from IP errors, implemented as a delayed work job, which
calls venus_sys_error_handler().
Right now, it has several issues:
1. It assumes that PM runtime resume never fails
2. It internally runs two while() loops that also assume that
PM runtime will never fail to go idle:
while (pm_runtime_active(core->dev_dec) || pm_runtime_active(core->dev_enc))
msleep(10);
...
while (core->pmdomains[0] && pm_runtime_active(core->pmdomains[0]))
usleep_range(1000, 1500);
3. It uses an OR to merge all return codes and then report to the user
4. If the hardware never recovers, it keeps running on every 10ms,
flooding the syslog with 2 messages (so, up to 200 messages
per second).
Rework the code, in order to prevent that, by:
1. check the return code from PM runtime resume;
2. don't let the while() loops run forever;
3. store the failed event;
4. use warn ratelimited when it fails to recover.
Fixes: af2c3834c8ca ("[media] media: venus: adding core part and helper functions")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>Trivial comments inline, otherwise based on no knowledge at all of the actual hardware, the fix looks sane. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
quoted hunk ↗ jump to hunk
--- drivers/media/platform/qcom/venus/core.c | 59 +++++++++++++++++++----- 1 file changed, 47 insertions(+), 12 deletions(-)diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c index 54bac7ec14c5..4d0482743c0a 100644 --- a/drivers/media/platform/qcom/venus/core.c +++ b/drivers/media/platform/qcom/venus/core.c@@ -78,22 +78,32 @@ static const struct hfi_core_ops venus_core_ops = { .event_notify = venus_event_notify, }; +#define RPM_WAIT_FOR_IDLE_MAX_ATTEMPTS 10 + static void venus_sys_error_handler(struct work_struct *work) { struct venus_core *core = container_of(work, struct venus_core, work.work); - int ret = 0; + int ret, i, max_attempts = RPM_WAIT_FOR_IDLE_MAX_ATTEMPTS; + bool failed = false; + const char *err_msg = ""; - pm_runtime_get_sync(core->dev); + ret = pm_runtime_get_sync(core->dev); + if (ret < 0) { + err_msg = "resume runtime PM\n";
Will end up with two newlines I think as %s\n" later.
quoted hunk ↗ jump to hunk
+ max_attempts = 0; + failed = true; + } hfi_core_deinit(core, true); - dev_warn(core->dev, "system error has occurred, starting recovery!\n"); - mutex_lock(&core->lock); - while (pm_runtime_active(core->dev_dec) || pm_runtime_active(core->dev_enc)) + for (i = 0; i < max_attempts; i++) { + if (!pm_runtime_active(core->dev_dec) && !pm_runtime_active(core->dev_enc)) + break; msleep(10); + } venus_shutdown(core);@@ -101,31 +111,56 @@ static void venus_sys_error_handler(struct work_struct *work) pm_runtime_put_sync(core->dev); - while (core->pmdomains[0] && pm_runtime_active(core->pmdomains[0])) + for (i = 0; i < max_attempts; i++) { + if (!core->pmdomains[0] || !pm_runtime_active(core->pmdomains[0])) + break; usleep_range(1000, 1500); + } hfi_reinit(core); - pm_runtime_get_sync(core->dev); + ret = pm_runtime_get_sync(core->dev); + if (ret < 0) { + err_msg = "resume runtime PM\n"; + max_attempts = 0;
This is after the last use of max_attempts, so no point in setting it to zero.
+ failed = true;
+ }
- ret |= venus_boot(core);
- ret |= hfi_core_resume(core, true);
+ ret = venus_boot(core);
+ if (ret && !failed) {
+ err_msg = "boot Venus\n";
+ failed = true;
+ }
+
+ ret = hfi_core_resume(core, true);
+ if (ret && !failed) {
+ err_msg = "resume HFI\n";
+ failed = true;
+ }
enable_irq(core->irq);
mutex_unlock(&core->lock);
- ret |= hfi_core_init(core);
+ ret = hfi_core_init(core);
+ if (ret && !failed) {
+ err_msg = "init HFI\n";
+ failed = true;
+ }
pm_runtime_put_sync(core->dev);
- if (ret) {
+ if (failed) {
disable_irq_nosync(core->irq);
- dev_warn(core->dev, "recovery failed (%d)\n", ret);
+ dev_warn_ratelimited(core->dev,
+ "System error has occurred, recovery failed to %s\n",
+ err_msg);
schedule_delayed_work(&core->work, msecs_to_jiffies(10));
return;
}
+ dev_warn(core->dev, "system error has occurred (recovered)\n");
+
mutex_lock(&core->lock);
core->sys_error = false;
mutex_unlock(&core->lock);