Messages in this thread | | | Date | Mon, 22 May 2023 15:01:53 +0800 | Subject | Re: [PATCH v4] bus: mhi: host: Skip MHI reset if device is in RDDM | From | Qiang Yu <> |
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On 5/19/2023 9:51 PM, Manivannan Sadhasivam wrote: > On Thu, May 18, 2023 at 02:22:39PM +0800, Qiang Yu wrote: >> 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> >> --- >> v1->v2: use ~75 columns in commit text, add Fixes tag >> v2->v3: update Fixes tag >> v3->v4: add review tag and CC stable >> >> 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 0834590..8a4362d 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) > Do we really need to check for rddm_image? Wouldn't the EE check sufficient > enough? > > In that case, the check can be moved to the prior if condition. > > - Mani
If rddm_image is NULL, that means this device does not support RDDM. In this case, it is unnecessary to access MMIO register.
>> + 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; >> -- >> 2.7.4 >> >>
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