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@xxxxxxxxxxxxxx> --- drivers/bus/mhi/core/pm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index dc83d65..239619b 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -9,6 +9,7 @@ #include <linux/dma-direction.h> #include <linux/dma-mapping.h> #include <linux/interrupt.h> +#include <linux/iopoll.h> #include <linux/list.h> #include <linux/mhi.h> #include <linux/module.h> @@ -760,6 +761,7 @@ 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 +831,24 @@ 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 = readl_poll_timeout(mhi_cntrl->regs + MHICTRL, val, + !(val & MHICTRL_RESET_MASK), 1000, + mhi_cntrl->timeout_ms * 1000); + if (ret) { + 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.