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@xxxxxxxxxxxxxxx>
> Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions")
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
> Reviewed-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
> ---
> 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
> + 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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