Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4b3ca621 authored by Veerabhadrarao Badiganti's avatar Veerabhadrarao Badiganti Committed by Gerrit - the friendly Code Review server
Browse files

msm: mhi_dev: Ensure the flush list is empty for a stopped channel 



If a channel gets stopped, while there are some outstanding requests/
transfers with IPA, then we simply ignore the completion from IPA.
But we must have already added the transfer-completion-event to the
flush list before submitting the transfer to IPA.

There is a possibility that we flush these stale events along with new
flush events (for new requests) when the channel gets re-started.
This un-intentional completion event can lead to out-of-sequence
events at the host.

So while stopping a channel, ensure all elements in the flush list
of that channel are discarded and the flush list is empty.

Change-Id: I04445b1f9f4d2d4fce0b8a96277517de14481ead
Signed-off-by: default avatarVeerabhadrarao Badiganti <vbadigan@codeaurora.org>
parent 8bbe4188

drivers/platform/msm/mhi_dev/mhi.c

+16 −0
Original line number Diff line number Diff line
@@ -1841,6 +1841,8 @@ static void mhi_dev_process_reset_cmd(struct mhi_dev *mhi, int ch_id) 
	int rc = 0;

	struct mhi_dev_channel *ch;

	struct mhi_addr host_addr;

	struct event_req *itr, *tmp;

	unsigned long flags;



	rc = mhi_dev_mmio_disable_chdb_a7(mhi, ch_id);

	if (rc) {
@@ -1855,6 +1857,20 @@ static void mhi_dev_process_reset_cmd(struct mhi_dev *mhi, int ch_id) 
	}



	ch = &mhi->ch[ch_id];

	mhi_log(MHI_MSG_VERBOSE, "Processing reset cmd for ch%d\n", ch_id);

	/*

	 * Ensure that the completions that are present in the flush list are

	 * removed from the list and discarded before stopping the channel.

	 * Otherwise, those stale events may get flushed along with a valid

	 * event in the next flush operation.

	 */

	spin_lock_irqsave(&mhi_ctx->lock, flags);

	list_for_each_entry_safe(itr, tmp, &ch->flush_event_req_buffers, list) {

		list_del(&itr->list);

		kfree(itr);

	}

	spin_unlock_irqrestore(&mhi_ctx->lock, flags);



	/* hard stop and set the channel to stop */

	mhi->ch_ctx_cache[ch_id].ch_state =

				MHI_DEV_CH_STATE_DISABLED;