linux/drivers/bus/mhi
Jeffrey Hugo 1d1493bdc2 bus: mhi: host: Use mhi_tryset_pm_state() for setting fw error state
If firmware loading fails, the controller's pm_state is updated to
MHI_PM_FW_DL_ERR unconditionally.  This can corrupt the pm_state as the
update is not done under the proper lock, and also does not validate
the state transition.  The firmware loading can fail due to a detected
syserr, but if MHI_PM_FW_DL_ERR is unconditionally set as the pm_state,
the handling of the syserr can break when it attempts to transition from
syserr detect, to syserr process.

By grabbing the lock, we ensure we don't race with some other pm_state
update.  By using mhi_try_set_pm_state(), we check that the transition
to MHI_PM_FW_DL_ERR is valid via the state machine logic.  If it is not
valid, then some other transition is occurring like syserr processing, and
we assume that will resolve the firmware loading error.

Fixes: 12e050c77b ("bus: mhi: core: Move to an error state on any firmware load failure")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://lore.kernel.org/r/1681142292-27571-3-git-send-email-quic_jhugo@quicinc.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
2023-04-10 21:32:55 +05:30
..
ep bus: mhi: ep: Demote unsupported channel error log to debug 2023-03-07 22:17:29 +05:30
host bus: mhi: host: Use mhi_tryset_pm_state() for setting fw error state 2023-04-10 21:32:55 +05:30
common.h bus: mhi: ep: Add support for sending events to the host 2022-04-26 13:17:41 +02:00
Kconfig bus: mhi: ep: Add support for registering MHI endpoint controllers 2022-04-26 13:17:40 +02:00
Makefile bus: mhi: Update Makefile to used Kconfig flags 2023-01-27 12:30:53 +05:30