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From: Bhaumik Bhatt <bbhatt@codeaurora.org>
To: manivannan.sadhasivam@linaro.org
Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
	jhugo@codeaurora.org, linux-kernel@vger.kernel.org,
	carl.yin@quectel.com, naveen.kumar@quectel.com,
	loic.poulain@linaro.org, Bhaumik Bhatt <bbhatt@codeaurora.org>
Subject: [PATCH v8 5/9] bus: mhi: core: Hold device wake for channel update commands
Date: Thu,  1 Apr 2021 14:16:14 -0700	[thread overview]
Message-ID: <1617311778-1254-6-git-send-email-bbhatt@codeaurora.org> (raw)
In-Reply-To: <1617311778-1254-1-git-send-email-bbhatt@codeaurora.org>

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: Bhaumik Bhatt <bbhatt@codeaurora.org>
---
 drivers/bus/mhi/core/main.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 94fdbf7..989a2a8 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1278,16 +1278,18 @@ 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,
@@ -1296,9 +1298,12 @@ 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) ?
@@ -1309,7 +1314,11 @@ 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,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


  parent reply	other threads:[~2021-04-01 21:16 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01 21:16 Bhaumik Bhatt
2021-04-01 21:16 ` [PATCH v8 1/9] bus: mhi: core: Allow sending the STOP channel command Bhaumik Bhatt
2021-05-04 17:40   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 2/9] bus: mhi: core: Clear context for stopped channels from remove() Bhaumik Bhatt
2021-05-04 17:41   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 3/9] bus: mhi: core: Improvements to the channel handling state machine Bhaumik Bhatt
2021-04-07  6:26   ` Manivannan Sadhasivam
2021-05-04 17:43   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 4/9] bus: mhi: core: Update debug messages to use client device Bhaumik Bhatt
2021-04-07  6:27   ` Manivannan Sadhasivam
2021-05-04 17:45   ` Jeffrey Hugo
2021-04-01 21:16 ` Bhaumik Bhatt [this message]
2021-04-07  6:31   ` [PATCH v8 5/9] bus: mhi: core: Hold device wake for channel update commands Manivannan Sadhasivam
2021-05-04 17:46   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 6/9] bus: mhi: core: Clear configuration from channel context during reset Bhaumik Bhatt
2021-05-04 17:48   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 7/9] bus: mhi: core: Check channel execution environment before issuing reset Bhaumik Bhatt
2021-05-04 17:49   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 8/9] bus: mhi: core: Remove __ prefix for MHI channel unprepare function Bhaumik Bhatt
2021-05-04 17:50   ` Jeffrey Hugo
2021-04-01 21:16 ` [PATCH v8 9/9] bus: mhi: Improve documentation on channel transfer setup APIs Bhaumik Bhatt
2021-05-04 17:51   ` Jeffrey Hugo
2021-04-07  6:56 ` your mail Manivannan Sadhasivam

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