Commit 73b7aebc authored by Bhaumik Bhatt's avatar Bhaumik Bhatt Committed by Manivannan Sadhasivam
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bus: mhi: core: Hold device wake for channel update commands 



MHI host can fail early if device is in a bad state by attempting
to assert device wake and holding the runtime PM vote before
sending a channel update command instead of performing a wake
toggle and waiting for a timeout if the send were to fail. This
can help improve the design and enable shorter wait periods for
device to respond as votes are already held.

Signed-off-by: default avatarBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1617311778-1254-6-git-send-email-bbhatt@codeaurora.org


Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
parent cde61bb0

drivers/bus/mhi/core/main.c

+14 −5
Original line number Diff line number Diff line
@@ -1286,16 +1286,18 @@ static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl, 
		return -EINVAL;

	}



	mhi_cntrl->wake_toggle(mhi_cntrl);

	/* 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);

	mhi_cntrl->runtime_put(mhi_cntrl);



	reinit_completion(&mhi_chan->completion);

	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));

		return ret;

		goto exit_channel_update;

	}



	ret = wait_for_completion_timeout(&mhi_chan->completion,
@@ -1304,9 +1306,12 @@ static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl, 
		dev_err(dev,

			"%d: Failed to receive %s channel command completion\n",

			mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));

		return -EIO;

		ret = -EIO;

		goto exit_channel_update;

	}



	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) ?
@@ -1317,7 +1322,11 @@ static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl, 
	dev_dbg(dev, "%d: Channel state change to %s successful\n",

		mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));



	return 0;

exit_channel_update:

	mhi_cntrl->runtime_put(mhi_cntrl);

	mhi_device_put(mhi_cntrl->mhi_dev);



	return ret;

}



static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,