bus: mhi: core: Cache intmod from mhi event to mhi channel

Driver is using zero initialized intmod value from mhi channel when
configuring TRE for bei field. This prevents interrupt moderation to
take effect in case it is supported by an event ring. Fix this by
copying intmod value from associated event ring to mhi channel upon
registering mhi controller.

Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Bhaumik Bhatt <bbhatt@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/20200521170249.21795-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/init.c

@@ -863,6 +863,10 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 		mutex_init(&mhi_chan->mutex);
 		init_completion(&mhi_chan->completion);
 		rwlock_init(&mhi_chan->lock);
+
+		/* used in setting bei field of TRE */
+		mhi_event = &mhi_cntrl->mhi_event[mhi_chan->er_index];
+		mhi_chan->intmod = mhi_event->intmod;
 	}
 
 	if (mhi_cntrl->bounce_buf) {