On Mon, Mar 29, 2021 at 07:11:43PM -0700, Bhaumik Bhatt wrote: > Improve the channel handling state machine such that all commands > go through a common function and a validation process to ensure > that the state machine is not violated in any way and adheres to > the MHI specification. Using this common function allows MHI to: > 1. Fail early if device is in a bad state by attempting to assert > device wake before sending a channel update command instead of > performing a wake toggle and waiting longer for the send to fail > 2. Use channel specific print messages to accurately identify the > use client device for the channel(s) being updated > 3. Eliminate unnecessary debug messages and code duplication
Please don't club these changes in a single patch. Split them as individual patches. Thanks, Mani > > Signed-off-by: Bhaumik Bhatt <[email protected]> > Reviewed-by: Hemant Kumar <[email protected]> > --- > drivers/bus/mhi/core/init.c | 6 ++ > drivers/bus/mhi/core/internal.h | 12 +++ > drivers/bus/mhi/core/main.c | 172 > ++++++++++++++++++++++------------------ > 3 files changed, 114 insertions(+), 76 deletions(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index bd62efcb..64846c4 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -54,6 +54,12 @@ const char * const mhi_state_str[MHI_STATE_MAX] = { > [MHI_STATE_SYS_ERR] = "SYS_ERR", > }; > > +const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = { > + [MHI_CH_STATE_TYPE_RESET] = "RESET", > + [MHI_CH_STATE_TYPE_STOP] = "STOP", > + [MHI_CH_STATE_TYPE_START] = "START", > +}; > + > static const char * const mhi_pm_state_str[] = { > [MHI_PM_STATE_DISABLE] = "DISABLE", > [MHI_PM_STATE_POR] = "POR", > diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h > index 6f37439..d8fd197 100644 > --- a/drivers/bus/mhi/core/internal.h > +++ b/drivers/bus/mhi/core/internal.h > @@ -369,6 +369,18 @@ enum mhi_ch_state { > MHI_CH_STATE_ERROR = 0x5, > }; > > +enum mhi_ch_state_type { > + MHI_CH_STATE_TYPE_RESET, > + MHI_CH_STATE_TYPE_STOP, > + MHI_CH_STATE_TYPE_START, > + MHI_CH_STATE_TYPE_MAX, > +}; > + > +extern const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX]; > +#define TO_CH_STATE_TYPE_STR(state) (((state) >= MHI_CH_STATE_TYPE_MAX) ? \ > + "INVALID_STATE" : \ > + mhi_ch_state_type_str[(state)]) > + > #define MHI_INVALID_BRSTMODE(mode) (mode != MHI_DB_BRST_DISABLE && \ > mode != MHI_DB_BRST_ENABLE) > > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > index 0dc3749..6c3234e 100644 > --- a/drivers/bus/mhi/core/main.c > +++ b/drivers/bus/mhi/core/main.c > @@ -1208,56 +1208,114 @@ int mhi_send_cmd(struct mhi_controller *mhi_cntrl, > return 0; > } > > -static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, > - struct mhi_chan *mhi_chan) > +static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl, > + struct mhi_chan *mhi_chan, > + enum mhi_ch_state_type to_state) > { > - int ret; > - struct device *dev = &mhi_cntrl->mhi_dev->dev; > + struct device *dev = &mhi_chan->mhi_dev->dev; > + enum mhi_cmd_type cmd = MHI_CMD_NOP; > + int ret = -EIO; > + > + dev_dbg(dev, "%d: Updating channel state to: %s\n", mhi_chan->chan, > + TO_CH_STATE_TYPE_STR(to_state)); > + > + switch (to_state) { > + case MHI_CH_STATE_TYPE_RESET: > + write_lock_irq(&mhi_chan->lock); > + if (mhi_chan->ch_state != MHI_CH_STATE_STOP && > + mhi_chan->ch_state != MHI_CH_STATE_ENABLED && > + mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) { > + write_unlock_irq(&mhi_chan->lock); > + return -EINVAL; > + } > + mhi_chan->ch_state = MHI_CH_STATE_DISABLED; > + write_unlock_irq(&mhi_chan->lock); > > - dev_dbg(dev, "Entered: unprepare channel:%d\n", mhi_chan->chan); > + cmd = MHI_CMD_RESET_CHAN; > + break; > + case MHI_CH_STATE_TYPE_STOP: > + if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED) > + return -EINVAL; > > - /* no more processing events for this channel */ > - mutex_lock(&mhi_chan->mutex); > - write_lock_irq(&mhi_chan->lock); > - if (mhi_chan->ch_state != MHI_CH_STATE_ENABLED && > - mhi_chan->ch_state != MHI_CH_STATE_SUSPENDED) { > - write_unlock_irq(&mhi_chan->lock); > - mutex_unlock(&mhi_chan->mutex); > - return; > + cmd = MHI_CMD_STOP_CHAN; > + break; > + case MHI_CH_STATE_TYPE_START: > + if (mhi_chan->ch_state != MHI_CH_STATE_STOP && > + mhi_chan->ch_state != MHI_CH_STATE_DISABLED) > + return -EINVAL; > + > + cmd = MHI_CMD_START_CHAN; > + break; > + default: > + dev_err(dev, "%d: Channel state update to %s not allowed\n", > + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); > + return -EINVAL; > } > > - mhi_chan->ch_state = MHI_CH_STATE_DISABLED; > - write_unlock_irq(&mhi_chan->lock); > + /* bring host and device out of suspended states */ > + ret = mhi_device_get_sync(mhi_cntrl->mhi_dev); > + if (ret) > + return ret; > + mhi_cntrl->runtime_get(mhi_cntrl); > > reinit_completion(&mhi_chan->completion); > - read_lock_bh(&mhi_cntrl->pm_lock); > - if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { > - read_unlock_bh(&mhi_cntrl->pm_lock); > - goto error_invalid_state; > + ret = mhi_send_cmd(mhi_cntrl, mhi_chan, cmd); > + if (ret) { > + dev_err(dev, "%d: Failed to send %s channel command\n", > + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); > + goto exit_channel_update; > } > > - mhi_cntrl->wake_toggle(mhi_cntrl); > - read_unlock_bh(&mhi_cntrl->pm_lock); > + ret = wait_for_completion_timeout(&mhi_chan->completion, > + msecs_to_jiffies(mhi_cntrl->timeout_ms)); > + if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) { > + dev_err(dev, > + "%d: Failed to receive %s channel command completion\n", > + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); > + ret = -EIO; > + goto exit_channel_update; > + } > > - mhi_cntrl->runtime_get(mhi_cntrl); > + ret = 0; > + > + if (to_state != MHI_CH_STATE_TYPE_RESET) { > + write_lock_irq(&mhi_chan->lock); > + mhi_chan->ch_state = (to_state == MHI_CH_STATE_TYPE_START) ? > + MHI_CH_STATE_ENABLED : MHI_CH_STATE_STOP; > + write_unlock_irq(&mhi_chan->lock); > + } > + > + dev_dbg(dev, "%d: Channel state change to %s successful\n", > + mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state)); > + > +exit_channel_update: > mhi_cntrl->runtime_put(mhi_cntrl); > - ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_RESET_CHAN); > - if (ret) > - goto error_invalid_state; > + mhi_device_put(mhi_cntrl->mhi_dev); > > - /* even if it fails we will still reset */ > - ret = wait_for_completion_timeout(&mhi_chan->completion, > - msecs_to_jiffies(mhi_cntrl->timeout_ms)); > - if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) > - dev_err(dev, > - "Failed to receive cmd completion, still resetting\n"); > + return ret; > +} > + > +static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl, > + struct mhi_chan *mhi_chan) > +{ > + int ret; > + struct device *dev = &mhi_chan->mhi_dev->dev; > + > + mutex_lock(&mhi_chan->mutex); > + > + /* no more processing events for this channel */ > + ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, > + MHI_CH_STATE_TYPE_RESET); > + if (ret) > + dev_err(dev, "%d: Failed to reset channel, still resetting\n", > + mhi_chan->chan); > > -error_invalid_state: > if (!mhi_chan->offload_ch) { > mhi_reset_chan(mhi_cntrl, mhi_chan); > mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan); > } > - dev_dbg(dev, "chan:%d successfully resetted\n", mhi_chan->chan); > + dev_dbg(dev, "%d: successfully reset\n", mhi_chan->chan); > + > mutex_unlock(&mhi_chan->mutex); > } > > @@ -1265,28 +1323,16 @@ int mhi_prepare_channel(struct mhi_controller > *mhi_cntrl, > struct mhi_chan *mhi_chan) > { > int ret = 0; > - struct device *dev = &mhi_cntrl->mhi_dev->dev; > - > - dev_dbg(dev, "Preparing channel: %d\n", mhi_chan->chan); > + struct device *dev = &mhi_chan->mhi_dev->dev; > > if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) { > - dev_err(dev, > - "Current EE: %s Required EE Mask: 0x%x for chan: %s\n", > - TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask, > - mhi_chan->name); > + dev_err(dev, "Current EE: %s Required EE Mask: 0x%x\n", > + TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask); > return -ENOTCONN; > } > > mutex_lock(&mhi_chan->mutex); > > - /* If channel is not in disable state, do not allow it to start */ > - if (mhi_chan->ch_state != MHI_CH_STATE_DISABLED) { > - ret = -EIO; > - dev_dbg(dev, "channel: %d is not in disabled state\n", > - mhi_chan->chan); > - goto error_init_chan; > - } > - > /* Check of client manages channel context for offload channels */ > if (!mhi_chan->offload_ch) { > ret = mhi_init_chan_ctxt(mhi_cntrl, mhi_chan); > @@ -1294,34 +1340,11 @@ int mhi_prepare_channel(struct mhi_controller > *mhi_cntrl, > goto error_init_chan; > } > > - reinit_completion(&mhi_chan->completion); > - read_lock_bh(&mhi_cntrl->pm_lock); > - if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { > - read_unlock_bh(&mhi_cntrl->pm_lock); > - ret = -EIO; > - goto error_pm_state; > - } > - > - mhi_cntrl->wake_toggle(mhi_cntrl); > - read_unlock_bh(&mhi_cntrl->pm_lock); > - mhi_cntrl->runtime_get(mhi_cntrl); > - mhi_cntrl->runtime_put(mhi_cntrl); > - > - ret = mhi_send_cmd(mhi_cntrl, mhi_chan, MHI_CMD_START_CHAN); > + ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, > + MHI_CH_STATE_TYPE_START); > if (ret) > goto error_pm_state; > > - ret = wait_for_completion_timeout(&mhi_chan->completion, > - msecs_to_jiffies(mhi_cntrl->timeout_ms)); > - if (!ret || mhi_chan->ccs != MHI_EV_CC_SUCCESS) { > - ret = -EIO; > - goto error_pm_state; > - } > - > - write_lock_irq(&mhi_chan->lock); > - mhi_chan->ch_state = MHI_CH_STATE_ENABLED; > - write_unlock_irq(&mhi_chan->lock); > - > /* Pre-allocate buffer for xfer ring */ > if (mhi_chan->pre_alloc) { > int nr_el = get_nr_avail_ring_elements(mhi_cntrl, > @@ -1359,9 +1382,6 @@ int mhi_prepare_channel(struct mhi_controller > *mhi_cntrl, > > mutex_unlock(&mhi_chan->mutex); > > - dev_dbg(dev, "Chan: %d successfully moved to start state\n", > - mhi_chan->chan); > - > return 0; > > error_pm_state: > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
