linux-kernel - [PATCH 5/5] bus: host: mhi: Need to honor sys_err at power

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Message-ID: <20250703-sriov_vdev_next-20250630-v1-5-87071d1047e3@quicinc.com>
Date: Thu, 3 Jul 2025 20:39:44 +0530
From: Vivek.Pernamitta@...cinc.com
To: Manivannan Sadhasivam <mani@...nel.org>
CC: <mhi@...ts.linux.dev>, <linux-arm-msm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Vivek Pernamitta <quic_vpernami@...cinc.com>
Subject: [PATCH 5/5] bus: host: mhi: Need to honor sys_err at power_up
 state

From: Vivek Pernamitta <quic_vpernami@...cinc.com>

In mhi_sync_power_up() host waits for device to enter in to mission mode
but SYS_ERR is an valid state, If device sends an SYS_ERR host will bail
out for wait_event_timeout() as MHI is in error state and calls
mhi_power_down which will teardown MHI driver probe.

If there is any SYS_ERR, sys_err handler needs to process SYS_ERR state
and queues the next state transition for device to bring in to Mission
mode, so mhi_sync_power_up() will wait for device to enter in to
mission mode.

Signed-off-by: Vivek Pernamitta <quic_vpernami@...cinc.com>
---
 drivers/bus/mhi/host/internal.h | 2 ++
 drivers/bus/mhi/host/pm.c       | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 1054e67bb450d2634771d092ed42bbdd63380472..00e46176654d8dc2f28b1535d9ef68233266ff3b 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -170,6 +170,8 @@ enum mhi_pm_state {
 							MHI_PM_IN_ERROR_STATE(pm_state))
 #define MHI_PM_IN_SUSPEND_STATE(pm_state)		(pm_state & \
 							(MHI_PM_M3_ENTER | MHI_PM_M3))
+#define MHI_PM_IN_BAD_STATE(pm_state)			((pm_state == MHI_PM_FW_DL_ERR) || \
+							(pm_state >= MHI_PM_SYS_ERR_FAIL))
 
 #define NR_OF_CMD_RINGS					1
 #define CMD_EL_PER_RING					128
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index 2af34980e14250cada75c981b690bc9581715212..ee50efc57cf713a7cf38a670cb49ab09a83b30ee 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -1280,7 +1280,7 @@ int mhi_sync_power_up(struct mhi_controller *mhi_cntrl)
 		mhi_cntrl->ready_timeout_ms : mhi_cntrl->timeout_ms;
 	wait_event_timeout(mhi_cntrl->state_event,
 			   MHI_IN_MISSION_MODE(mhi_cntrl->ee) ||
-			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
+			   MHI_PM_IN_BAD_STATE(mhi_cntrl->pm_state),
 			   msecs_to_jiffies(timeout_ms));
 
 	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -ETIMEDOUT;

-- 
2.34.1