bus: mhi: core: Abort suspends due to outgoing pending packets

[ Upstream commit 515847c ]

Add the missing check to abort suspends if a client driver has pending
outgoing packets to send to the device. This allows better utilization
of the MHI bus wherein clients on the host are not left waiting for
longer suspend or resume cycles to finish for data transfers.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200929175218.8178-4-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/bus/mhi/core/pm.c

@@ -686,7 +686,8 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 
 	/* Return busy if there are any pending resources */
-	if (atomic_read(&mhi_cntrl->dev_wake))
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_cntrl->pending_pkts))
 		return -EBUSY;
 
 	/* Take MHI out of M2 state */
@@ -712,7 +713,8 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
 
-	if (atomic_read(&mhi_cntrl->dev_wake)) {
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_cntrl->pending_pkts)) {
 		write_unlock_irq(&mhi_cntrl->pm_lock);
 		return -EBUSY;
 	}