This is a note to let you know that I've just added the patch titled
bus: mhi: host: Skip MHI reset if device is in RDDM
to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release during the merge window.
If you have any questions about this process, please let me know.
From cabce92dd805945a090dc6fc73b001bb35ed083a Mon Sep 17 00:00:00 2001 From: Qiang Yu quic_qianyu@quicinc.com Date: Thu, 18 May 2023 14:22:39 +0800 Subject: bus: mhi: host: Skip MHI reset if device is in RDDM
In RDDM EE, device can not process MHI reset issued by host. In case of MHI power off, host is issuing MHI reset and polls for it to get cleared until it times out. Since this timeout can not be avoided in case of RDDM, skip the MHI reset in this scenarios.
Cc: stable@vger.kernel.org Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions") Signed-off-by: Qiang Yu quic_qianyu@quicinc.com Reviewed-by: Jeffrey Hugo quic_jhugo@quicinc.com Reviewed-by: Manivannan Sadhasivam mani@kernel.org Link: https://lore.kernel.org/r/1684390959-17836-1-git-send-email-quic_qianyu@quic... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org --- drivers/bus/mhi/host/pm.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c index 083459028a4b..8a4362d75fc4 100644 --- a/drivers/bus/mhi/host/pm.c +++ b/drivers/bus/mhi/host/pm.c @@ -470,6 +470,10 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
/* Trigger MHI RESET so that the device will not access host memory */ if (!MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state)) { + /* Skip MHI RESET if in RDDM state */ + if (mhi_cntrl->rddm_image && mhi_get_exec_env(mhi_cntrl) == MHI_EE_RDDM) + goto skip_mhi_reset; + dev_dbg(dev, "Triggering MHI Reset in device\n"); mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
@@ -495,6 +499,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) } }
+skip_mhi_reset: dev_dbg(dev, "Waiting for all pending event ring processing to complete\n"); mhi_event = mhi_cntrl->mhi_event;