Hi Enric On 03.02.2020 10:33, Enric Balletbo Serra wrote: > Missatge de Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> del dia dv., > 31 de gen. 2020 a les 8:41: >> On 07.01.2020 23:06, Yicheng Li wrote: >>> RO and RW of EC may have different EC protocol version. If EC transitions >>> between RO and RW, but AP does not reboot (this is true for fingerprint >>> microcontroller / cros_fp, but not true for main ec / cros_ec), the AP >>> still uses the protocol version queried before transition, which can >>> cause problems. In the case of fingerprint microcontroller, this causes >>> AP to send the wrong version of EC_CMD_GET_NEXT_EVENT to RO in the >>> interrupt handler, which in turn prevents RO to clear the interrupt >>> line to AP, in an infinite loop. >>> >>> Once an EC_HOST_EVENT_INTERFACE_READY is received, we know that there >>> might have been a transition between RO and RW, so re-query the protocol. >>> >>> Change-Id: I49a51cc10d22a4ab9e75204a4c0c8819d5b3d282 >>> Signed-off-by: Yicheng Li <yichengli@xxxxxxxxxxxx> >> This patch landed recently in linux-next as commit >> 241a69ae8ea8e2defec751fe55dac1287aa044b8. Sadly, it causes following >> kernel oops on any key press on Samsung Exynos-based Chromebooks (Snow, >> Peach-Pit and Peach-Pi): > Many thanks for report the issue, we will take a look ASAP and revert > this commit meanwhile. Simply removing the BUG_ON() from cros_ec_get_host_event() function fixes the issue, but I don't know the protocol details to judge if this is the correct way of fixing it. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
