On 8/15/2018 8:01 PM, Rafał Miłecki wrote:
From: Rafał Miłecki <rafal@xxxxxxxxxx>
It may happen for FullMAC firmware to crash. It should be detected and
ideally somehow handled by a driver.
Since commit ff4445a8502c ("brcmfmac: expose device memory to
devcoredump subsystem") brcmfmac has BRCMF_E_PSM_WATCHDOG event handler
but it wasn't enough to detect all kind of crashes. E.g. Netgear R8000
(BCM4709A0 + 3 x BCM43602) user was exepriencing firmware crashes that
never resulted in passing BRCMF_E_PSM_WATCHDOG to the host driver.
Thanks, Rafał
The PSM watchdog is actually not a firmware crash. It means the lower
part of the stack, which runs in the d11 core aka PSM, did not complete
its work in the required timing budget.
That made me implement this trivial software watchdog that simply checks
periodically if firmware still replies to the commands.
Luckily this patch DOES NOT seem to be needed anymore since the commit
8a3ab2f38f16 ("brcmfmac: trigger memory dump upon firmware halt
signal"). That change allows brcmfmac to detect firmware crashes
successfully.
It can still miss a firmware crash if it happens really soon. Those
crashes mostly happens when trying to load firmware for chip revision A
on chip with revision B due to differences in code contained in ROM.
Regards,
Arend
This patch is being posted for research/debugging purposes only. It
SHOULD NOT be applied until someone notices a firmware crash that
doesn't trigger the BRCMF_D2H_DEV_FWHALT signal.
Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
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