| Message ID | 20220212182117.49438-19-manivannan.sadhasivam@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add initial support for MHI endpoint stack | expand |
On 2/12/22 12:21 PM, Manivannan Sadhasivam wrote: > Add support for handling MHI_RESET in MHI endpoint stack. MHI_RESET will > be issued by the host during shutdown and during error scenario so that > it can recover the endpoint device without restarting the whole device. > > MHI_RESET handling involves resetting the internal MHI registers, data > structures, state machines, resetting all channels/rings and setting > MHICTRL.RESET bit to 0. Additionally the device will also move to READY > state if the reset was due to SYS_ERR. > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> I might be getting tired out... But this looks good to me! Reviewed-by: Alex Elder <elder@linaro.org> > --- > drivers/bus/mhi/ep/main.c | 53 +++++++++++++++++++++++++++++++++++++++ > include/linux/mhi_ep.h | 2 ++ > 2 files changed, 55 insertions(+) > > diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c > index 14cb08de4263..ddedd0fb19aa 100644 > --- a/drivers/bus/mhi/ep/main.c > +++ b/drivers/bus/mhi/ep/main.c > @@ -471,6 +471,7 @@ static irqreturn_t mhi_ep_irq(int irq, void *data) > struct device *dev = &mhi_cntrl->mhi_dev->dev; > enum mhi_state state; > u32 int_value; > + bool mhi_reset; > > /* Acknowledge the interrupts */ > int_value = mhi_ep_mmio_read(mhi_cntrl, MHI_CTRL_INT_STATUS_A7); > @@ -479,6 +480,14 @@ static irqreturn_t mhi_ep_irq(int irq, void *data) > /* Check for ctrl interrupt */ > if (FIELD_GET(MHI_CTRL_INT_STATUS_A7_MSK, int_value)) { > dev_dbg(dev, "Processing ctrl interrupt\n"); > + mhi_ep_mmio_get_mhi_state(mhi_cntrl, &state, &mhi_reset); > + if (mhi_reset) { > + dev_info(dev, "Host triggered MHI reset!\n"); > + disable_irq_nosync(mhi_cntrl->irq); > + schedule_work(&mhi_cntrl->reset_work); > + return IRQ_HANDLED; > + } > + > mhi_ep_process_ctrl_interrupt(mhi_cntrl, state); > } > > @@ -559,6 +568,49 @@ static void mhi_ep_abort_transfer(struct mhi_ep_cntrl *mhi_cntrl) > mhi_cntrl->is_enabled = false; > } > > +static void mhi_ep_reset_worker(struct work_struct *work) > +{ > + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, reset_work); > + struct device *dev = &mhi_cntrl->mhi_dev->dev; > + enum mhi_state cur_state; > + int ret; > + > + mhi_ep_abort_transfer(mhi_cntrl); > + > + spin_lock_bh(&mhi_cntrl->state_lock); > + /* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */ > + mhi_ep_mmio_reset(mhi_cntrl); > + cur_state = mhi_cntrl->mhi_state; > + spin_unlock_bh(&mhi_cntrl->state_lock); > + > + /* > + * Only proceed further if the reset is due to SYS_ERR. The host will > + * issue reset during shutdown also and we don't need to do re-init in > + * that case. > + */ > + if (cur_state == MHI_STATE_SYS_ERR) { > + mhi_ep_mmio_init(mhi_cntrl); > + > + /* Set AMSS EE before signaling ready state */ > + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EP_AMSS_EE); > + > + /* All set, notify the host that we are ready */ > + ret = mhi_ep_set_ready_state(mhi_cntrl); > + if (ret) > + return; > + > + dev_dbg(dev, "READY state notification sent to the host\n"); > + > + ret = mhi_ep_enable(mhi_cntrl); > + if (ret) { > + dev_err(dev, "Failed to enable MHI endpoint: %d\n", ret); > + return; > + } > + > + enable_irq(mhi_cntrl->irq); > + } > +} > + > int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl) > { > struct device *dev = &mhi_cntrl->mhi_dev->dev; > @@ -827,6 +879,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, > > INIT_WORK(&mhi_cntrl->ring_work, mhi_ep_ring_worker); > INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker); > + INIT_WORK(&mhi_cntrl->reset_work, mhi_ep_reset_worker); > > mhi_cntrl->ring_wq = alloc_workqueue("mhi_ep_ring_wq", 0, 0); > if (!mhi_cntrl->ring_wq) { > diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h > index 4f86e7986c93..276d29fef465 100644 > --- a/include/linux/mhi_ep.h > +++ b/include/linux/mhi_ep.h > @@ -75,6 +75,7 @@ struct mhi_ep_db_info { > * @ring_wq: Dedicated workqueue for processing MHI rings > * @state_work: State transition worker > * @ring_work: Ring worker > + * @reset_work: Worker for MHI Endpoint reset > * @ch_db_list: List of queued channel doorbells > * @st_transition_list: List of state transitions > * @list_lock: Lock for protecting state transition and channel doorbell lists > @@ -126,6 +127,7 @@ struct mhi_ep_cntrl { > struct workqueue_struct *ring_wq; > struct work_struct state_work; > struct work_struct ring_work; > + struct work_struct reset_work; > > struct list_head ch_db_list; > struct list_head st_transition_list;
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c index 14cb08de4263..ddedd0fb19aa 100644 --- a/drivers/bus/mhi/ep/main.c +++ b/drivers/bus/mhi/ep/main.c @@ -471,6 +471,7 @@ static irqreturn_t mhi_ep_irq(int irq, void *data) struct device *dev = &mhi_cntrl->mhi_dev->dev; enum mhi_state state; u32 int_value; + bool mhi_reset; /* Acknowledge the interrupts */ int_value = mhi_ep_mmio_read(mhi_cntrl, MHI_CTRL_INT_STATUS_A7); @@ -479,6 +480,14 @@ static irqreturn_t mhi_ep_irq(int irq, void *data) /* Check for ctrl interrupt */ if (FIELD_GET(MHI_CTRL_INT_STATUS_A7_MSK, int_value)) { dev_dbg(dev, "Processing ctrl interrupt\n"); + mhi_ep_mmio_get_mhi_state(mhi_cntrl, &state, &mhi_reset); + if (mhi_reset) { + dev_info(dev, "Host triggered MHI reset!\n"); + disable_irq_nosync(mhi_cntrl->irq); + schedule_work(&mhi_cntrl->reset_work); + return IRQ_HANDLED; + } + mhi_ep_process_ctrl_interrupt(mhi_cntrl, state); } @@ -559,6 +568,49 @@ static void mhi_ep_abort_transfer(struct mhi_ep_cntrl *mhi_cntrl) mhi_cntrl->is_enabled = false; } +static void mhi_ep_reset_worker(struct work_struct *work) +{ + struct mhi_ep_cntrl *mhi_cntrl = container_of(work, struct mhi_ep_cntrl, reset_work); + struct device *dev = &mhi_cntrl->mhi_dev->dev; + enum mhi_state cur_state; + int ret; + + mhi_ep_abort_transfer(mhi_cntrl); + + spin_lock_bh(&mhi_cntrl->state_lock); + /* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */ + mhi_ep_mmio_reset(mhi_cntrl); + cur_state = mhi_cntrl->mhi_state; + spin_unlock_bh(&mhi_cntrl->state_lock); + + /* + * Only proceed further if the reset is due to SYS_ERR. The host will + * issue reset during shutdown also and we don't need to do re-init in + * that case. + */ + if (cur_state == MHI_STATE_SYS_ERR) { + mhi_ep_mmio_init(mhi_cntrl); + + /* Set AMSS EE before signaling ready state */ + mhi_ep_mmio_set_env(mhi_cntrl, MHI_EP_AMSS_EE); + + /* All set, notify the host that we are ready */ + ret = mhi_ep_set_ready_state(mhi_cntrl); + if (ret) + return; + + dev_dbg(dev, "READY state notification sent to the host\n"); + + ret = mhi_ep_enable(mhi_cntrl); + if (ret) { + dev_err(dev, "Failed to enable MHI endpoint: %d\n", ret); + return; + } + + enable_irq(mhi_cntrl->irq); + } +} + int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl) { struct device *dev = &mhi_cntrl->mhi_dev->dev; @@ -827,6 +879,7 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl, INIT_WORK(&mhi_cntrl->ring_work, mhi_ep_ring_worker); INIT_WORK(&mhi_cntrl->state_work, mhi_ep_state_worker); + INIT_WORK(&mhi_cntrl->reset_work, mhi_ep_reset_worker); mhi_cntrl->ring_wq = alloc_workqueue("mhi_ep_ring_wq", 0, 0); if (!mhi_cntrl->ring_wq) { diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h index 4f86e7986c93..276d29fef465 100644 --- a/include/linux/mhi_ep.h +++ b/include/linux/mhi_ep.h @@ -75,6 +75,7 @@ struct mhi_ep_db_info { * @ring_wq: Dedicated workqueue for processing MHI rings * @state_work: State transition worker * @ring_work: Ring worker + * @reset_work: Worker for MHI Endpoint reset * @ch_db_list: List of queued channel doorbells * @st_transition_list: List of state transitions * @list_lock: Lock for protecting state transition and channel doorbell lists @@ -126,6 +127,7 @@ struct mhi_ep_cntrl { struct workqueue_struct *ring_wq; struct work_struct state_work; struct work_struct ring_work; + struct work_struct reset_work; struct list_head ch_db_list; struct list_head st_transition_list;
Add support for handling MHI_RESET in MHI endpoint stack. MHI_RESET will be issued by the host during shutdown and during error scenario so that it can recover the endpoint device without restarting the whole device. MHI_RESET handling involves resetting the internal MHI registers, data structures, state machines, resetting all channels/rings and setting MHICTRL.RESET bit to 0. Additionally the device will also move to READY state if the reset was due to SYS_ERR. Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> --- drivers/bus/mhi/ep/main.c | 53 +++++++++++++++++++++++++++++++++++++++ include/linux/mhi_ep.h | 2 ++ 2 files changed, 55 insertions(+)