Hi Mani, On 2020-10-30 23:54, Manivannan Sadhasivam wrote:
It had to be done for 11/12 and 12/12 (last two) patches of the series. It's a much cleaner approach and allows us to handle states better. We should be moving the dev_state and EE to "Reset" and "Disable" states soon enough when a shutdown is initiated and we can resolve bugs such as freeing the IRQs for a shutdown sooner as well. Since these differences in shutdown versus SYS_ERROR processing are already increasingly apparent and more could come, this patch had to stepHi Bhaumik,On 31 October 2020 1:04:07 AM IST, Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx> wrote:Hi Mani, On 2020-10-30 07:06, Manivannan Sadhasivam wrote:On Thu, Oct 29, 2020 at 09:10:55PM -0700, Bhaumik Bhatt wrote:Currently, there exist a set of if...else statements in the mhi_pm_disable_transition() function which make handling system error and disable transitions differently complex. To make that cleaner and facilitate differences in behavior, separate these two transitions for MHI host.And this results in a lot of duplicated code :/ Thanks, ManiI knew this was coming. Mainly, we can avoid adding confusing if...else statements that plague the current mhi_pm_disable_transition() functionand inreturn for some duplicate code, we can make handling separate use caseseasier as they could pop-up anytime in the future.If that happens then do it but now, please no. Thanks, Mani
in.bus: mhi: core: Mark and maintain device states early on after power down
bus: mhi: core: Remove MHI event ring IRQ handlers when powering down
Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx> --- drivers/bus/mhi/core/pm.c | 159 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 137 insertions(+), 22 deletions(-) diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index 1d04e401..347ae7d 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -444,7 +444,7 @@ static int mhi_pm_mission_mode_transition(structmhi_controller *mhi_cntrl) return ret; } -/* Handle SYS_ERR and Shutdown transitions */ +/* Handle shutdown transitions */ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, enum mhi_pm_state transition_state) { @@ -460,10 +460,6 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, to_mhi_pm_state_str(mhi_cntrl->pm_state), to_mhi_pm_state_str(transition_state)); - /* We must notify MHI control driver so it can clean up first */ - if (transition_state == MHI_PM_SYS_ERR_PROCESS) - mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR); - mutex_lock(&mhi_cntrl->pm_mutex); write_lock_irq(&mhi_cntrl->pm_lock); prev_state = mhi_cntrl->pm_state; @@ -502,11 +498,8 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, MHICTRL_RESET_SHIFT, &in_reset) || !in_reset, timeout); - if ((!ret || in_reset) && cur_state == MHI_PM_SYS_ERR_PROCESS) { + if (!ret || in_reset) dev_err(dev, "Device failed to exit MHI Reset state\n"); - mutex_unlock(&mhi_cntrl->pm_mutex); - return; - } /* * Device will clear BHI_INTVEC as a part of RESET processing, @@ -566,19 +559,142 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl, er_ctxt->wp = er_ctxt->rbase; } - if (cur_state == MHI_PM_SYS_ERR_PROCESS) { - mhi_ready_state_transition(mhi_cntrl); - } else { - /* Move to disable state */ - write_lock_irq(&mhi_cntrl->pm_lock); - cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE); - write_unlock_irq(&mhi_cntrl->pm_lock); - if (unlikely(cur_state != MHI_PM_DISABLE)) - dev_err(dev, "Error moving from PM state: %s to: %s\n", - to_mhi_pm_state_str(cur_state), - to_mhi_pm_state_str(MHI_PM_DISABLE)); + /* Move to disable state */ + write_lock_irq(&mhi_cntrl->pm_lock); + cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_DISABLE); + write_unlock_irq(&mhi_cntrl->pm_lock); + if (unlikely(cur_state != MHI_PM_DISABLE)) + dev_err(dev, "Error moving from PM state: %s to: %s\n", + to_mhi_pm_state_str(cur_state), + to_mhi_pm_state_str(MHI_PM_DISABLE)); + + dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n", + to_mhi_pm_state_str(mhi_cntrl->pm_state), + TO_MHI_STATE_STR(mhi_cntrl->dev_state)); + + mutex_unlock(&mhi_cntrl->pm_mutex); +} + +/* Handle system error transitions */ +static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl) +{ + enum mhi_pm_state cur_state, prev_state; + struct mhi_event *mhi_event; + struct mhi_cmd_ctxt *cmd_ctxt; + struct mhi_cmd *mhi_cmd; + struct mhi_event_ctxt *er_ctxt; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + int ret, i; + + dev_dbg(dev, "Transitioning from PM state: %s to: %s\n", + to_mhi_pm_state_str(mhi_cntrl->pm_state), + to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS)); + + /* We must notify MHI control driver so it can clean up first */ + mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_SYS_ERROR); + + mutex_lock(&mhi_cntrl->pm_mutex); + write_lock_irq(&mhi_cntrl->pm_lock); + prev_state = mhi_cntrl->pm_state; + cur_state = mhi_tryset_pm_state(mhi_cntrl,MHI_PM_SYS_ERR_PROCESS);+ write_unlock_irq(&mhi_cntrl->pm_lock); + + if (cur_state != MHI_PM_SYS_ERR_PROCESS) { + dev_err(dev, "Failed to transition from PM state: %s to: %s\n", + to_mhi_pm_state_str(cur_state), + to_mhi_pm_state_str(MHI_PM_SYS_ERR_PROCESS)); + goto exit_sys_error_transition; + } + + mhi_cntrl->ee = MHI_EE_DISABLE_TRANSITION; + mhi_cntrl->dev_state = MHI_STATE_RESET; + + /* Wake up threads waiting for state transition */ + wake_up_all(&mhi_cntrl->state_event); + + /* Trigger MHI RESET so that the device will not access hostmemory*/ + if (MHI_REG_ACCESS_VALID(prev_state)) { + u32 in_reset = -1; + unsigned long timeout = msecs_to_jiffies(mhi_cntrl->timeout_ms); + + dev_dbg(dev, "Triggering MHI Reset in device\n"); + mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET); + + /* Wait for the reset bit to be cleared by the device */ + ret = wait_event_timeout(mhi_cntrl->state_event, + mhi_read_reg_field(mhi_cntrl, + mhi_cntrl->regs, + MHICTRL, + MHICTRL_RESET_MASK, + MHICTRL_RESET_SHIFT, + &in_reset) || + !in_reset, timeout); + if (!ret || in_reset) { + dev_err(dev, "Device failed to exit MHI Reset state\n"); + goto exit_sys_error_transition; + } + + /* + * Device will clear BHI_INTVEC as a part of RESET processing, + * hence re-program it + */ + mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); + } + + dev_dbg(dev, + "Waiting for all pending event ring processing to complete\n"); + mhi_event = mhi_cntrl->mhi_event; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) { + if (mhi_event->offload_ev) + continue; + tasklet_kill(&mhi_event->task); } + /* Release lock and wait for all pending threads to complete */ + mutex_unlock(&mhi_cntrl->pm_mutex); + dev_dbg(dev, "Waiting for all pending threads to complete\n"); + wake_up_all(&mhi_cntrl->state_event); + + dev_dbg(dev, "Reset all active channels and remove MHIdevices\n");+ device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); + + mutex_lock(&mhi_cntrl->pm_mutex); + + WARN_ON(atomic_read(&mhi_cntrl->dev_wake)); + WARN_ON(atomic_read(&mhi_cntrl->pending_pkts)); + + /* Reset the ev rings and cmd rings */ + dev_dbg(dev, "Resetting EV CTXT and CMD CTXT\n"); + mhi_cmd = mhi_cntrl->mhi_cmd; + cmd_ctxt = mhi_cntrl->mhi_ctxt->cmd_ctxt; + for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) { + struct mhi_ring *ring = &mhi_cmd->ring; + + ring->rp = ring->base; + ring->wp = ring->base; + cmd_ctxt->rp = cmd_ctxt->rbase; + cmd_ctxt->wp = cmd_ctxt->rbase; + } + + mhi_event = mhi_cntrl->mhi_event; + er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt; + for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++, + mhi_event++) { + struct mhi_ring *ring = &mhi_event->ring; + + /* Skip offload events */ + if (mhi_event->offload_ev) + continue; + + ring->rp = ring->base; + ring->wp = ring->base; + er_ctxt->rp = er_ctxt->rbase; + er_ctxt->wp = er_ctxt->rbase; + } + + mhi_ready_state_transition(mhi_cntrl); + +exit_sys_error_transition: dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n", to_mhi_pm_state_str(mhi_cntrl->pm_state), TO_MHI_STATE_STR(mhi_cntrl->dev_state)); @@ -666,8 +782,7 @@ void mhi_pm_st_worker(struct work_struct *work) mhi_ready_state_transition(mhi_cntrl); break; case DEV_ST_TRANSITION_SYS_ERR: - mhi_pm_disable_transition - (mhi_cntrl, MHI_PM_SYS_ERR_PROCESS); + mhi_pm_sys_error_transition(mhi_cntrl); break; case DEV_ST_TRANSITION_DISABLE: mhi_pm_disable_transition -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative ProjectThanks, Bhaumik
Thanks, Bhaumik --The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
