[PATCH] bus: mhi: pm: Change mhi_pm_resume timeout value

[Loic Poulain <loic.poulain@linaro.org>]

mhi_cntrl->timeout_ms is set by the controller and indicates the
maximum amount of time the controller device will take to be ready.
In case of PCI modems, this value is quite high given modems can take
up to 15 seconds from cold boot to be ready.

Reusing this value in mhi_pm_resume can cause huge resuming latency
and delay the whole system resume (in case of system wide suspend/
resume), leading to bad use experience.

This change adjusts the resume timeout to a fixed 2s value, which is
more than enough for any MHI device for exiting M3.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
---
 drivers/bus/mhi/core/pm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 0cd6445..e2d83a9 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -17,6 +17,8 @@
 #include <linux/wait.h>
 #include "internal.h"
 
+#define MHI_PM_RESUME_TIMEOUT_MS 2000
+
 /*
  * Not all MHI state transitions are synchronous. Transitions like Linkdown,
  * SYS_ERR, and shutdown can happen anytime asynchronously. This function will
@@ -942,7 +944,7 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
 	ret = wait_event_timeout(mhi_cntrl->state_event,
 				 mhi_cntrl->dev_state == MHI_STATE_M0 ||
 				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
-				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
+				 msecs_to_jiffies(MHI_PM_RESUME_TIMEOUT_MS));
 
 	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
 		dev_err(dev,
-- 
2.7.4