v5: -Use fsleep in place of udelay or usleep_range to accommodate better delay use -Drop patch for polling during RDDM panic path as new API cannot be used there v4: -Added reviewed-by tag -Return appropriate error code from mhi_poll_reg_field() -Fixed bug where mhi_poll_reg_field() returns success if polling times out -Added an interval_us variable in mhi_ready_state_transition() v3: -Removed config changes that crept in in the first patch v2: -Addressed review comments -Introduce new patch for to use controller defined read_reg() for polling -Add usage in RDDM download panic path as well Use polling instead of interrupt driven approach to wait for MHI ready state. In certain devices, it is likely that there is no incoming MHI interrupt for a transition to MHI READY state. One such example is the move from Pass Through to an SBL or AMSS execution environment. In order to facilitate faster bootup times as there is no need to wait until timeout_ms completes, MHI host can poll every 25 milliseconds to check if device has entered MHI READY until a maximum timeout of twice the timeout_ms is reached. This patch series has been tested on an arm64 device. Bhaumik Bhatt (2): bus: mhi: core: Introduce internal register poll helper function bus: mhi: core: Move to polling method to wait for MHI ready drivers/bus/mhi/core/internal.h | 3 +++ drivers/bus/mhi/core/main.c | 23 +++++++++++++++++++++++ drivers/bus/mhi/core/pm.c | 32 +++++++++++++++----------------- 3 files changed, 41 insertions(+), 17 deletions(-) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project