On Thu, May 07, 2020 at 10:19:31AM -0600, Jeffrey Hugo wrote:
> The MHI device may be in the syserr state when we attempt to init it in
> power_up(). Since we have no local state, the handling is simple -
> reset the device and wait for it to transition out of the reset state.
>
> Signed-off-by: Jeffrey Hugo <jh...@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
Will apply this patch to mhi-next and include in the 5.8 series.
Thanks,
Mani
> ---
>
> v4:
> -Implemented Hemant's suggested solution from v2. The spec will be amended
> to indicate the intvec interrupt will be triggered for the reset state change
> which matches the current implementations and enables Hemant's solution to
> be used, which is cleaner.
>
> drivers/bus/mhi/core/pm.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index dc83d65..ddef693 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -760,6 +760,7 @@ static void mhi_deassert_dev_wake(struct mhi_controller
> *mhi_cntrl,
>
> int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> {
> + enum mhi_state state;
> enum mhi_ee_type current_ee;
> enum dev_st_transition next_state;
> struct device *dev = &mhi_cntrl->mhi_dev->dev;
> @@ -829,6 +830,32 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> goto error_bhi_offset;
> }
>
> + state = mhi_get_mhi_state(mhi_cntrl);
> + if (state == MHI_STATE_SYS_ERR) {
> + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
> + ret = wait_event_timeout(mhi_cntrl->state_event,
> + MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) ||
> + mhi_read_reg_field(mhi_cntrl,
> + mhi_cntrl->regs,
> + MHICTRL,
> + MHICTRL_RESET_MASK,
> + MHICTRL_RESET_SHIFT,
> + &val) ||
> + !val,
> + msecs_to_jiffies(mhi_cntrl->timeout_ms));
> + if (ret) {
> + ret = -EIO;
> + dev_info(dev, "Failed to reset MHI due to syserr
> state\n");
> + goto error_bhi_offset;
> + }
> +
> + /*
> + * device cleares INTVEC as part of RESET processing,
> + * re-program it
> + */
> + mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0);
> + }
> +
> /* Transition to next state */
> next_state = MHI_IN_PBL(current_ee) ?
> DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY;
> --
> Qualcomm Technologies, Inc. is a member of the
> Code Aurora Forum, a Linux Foundation Collaborative Project.
