bus: mhi: core: Handle syserr during power_up

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 <jhugo@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200521170249.21795-15-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index de5abb26bcae16ae25f178ff8152b7b67b6b205e..7960980780832b787e4f84df1ae90724f9d7b19d 100644 (file)
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -906,6 +906,7 @@ 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;
@@ -975,6 +976,32 @@ 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;