bus: mhi: core: Skip handling BHI irq if MHI reg access is not allowed

Driver continues handling of BHI interrupt even if MHI register access
is not allowed. By doing so it calls the status call back and performs
early notification for the MHI client. This is not needed when MHI
register access is not allowed. Hence skip the handling in this case and
return. Also add debug log to print device state, local EE and device EE
when reg access is valid.

Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200521170249.21795-12-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/main.c

@@ -369,22 +369,29 @@ irqreturn_t mhi_irq_handler(int irq_number, void *dev)
 	return IRQ_HANDLED;
 }
 
-irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *dev)
+irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
 {
-	struct mhi_controller *mhi_cntrl = dev;
+	struct mhi_controller *mhi_cntrl = priv;
+	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 	enum mhi_state state = MHI_STATE_MAX;
 	enum mhi_pm_state pm_state = 0;
 	enum mhi_ee_type ee = 0;
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
-	if (MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
-		state = mhi_get_mhi_state(mhi_cntrl);
-		ee = mhi_cntrl->ee;
-		mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
+	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state)) {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		goto exit_intvec;
 	}
 
+	state = mhi_get_mhi_state(mhi_cntrl);
+	ee = mhi_cntrl->ee;
+	mhi_cntrl->ee = mhi_get_exec_env(mhi_cntrl);
+	dev_dbg(dev, "local ee:%s device ee:%s dev_state:%s\n",
+		TO_MHI_EXEC_STR(mhi_cntrl->ee), TO_MHI_EXEC_STR(ee),
+		TO_MHI_STATE_STR(state));
+
 	if (state == MHI_STATE_SYS_ERR) {
-		dev_dbg(&mhi_cntrl->mhi_dev->dev, "System error detected\n");
+		dev_dbg(dev, "System error detected\n");
 		pm_state = mhi_tryset_pm_state(mhi_cntrl,
 					       MHI_PM_SYS_ERR_DETECT);
 	}