Commit 20c46f6f authored Oct 25, 2021 by Ritesh Kumar Committed by Gerrit - the friendly Code Review server Nov 17, 2021

disp: msm: dsi: remove early return from dma_cmd_wait_for_done



In ASYNC wait mode, next command kickoff can happen before previous
command ISR execution is completed in below sequence:

ASYNC command A -> triggered

dsi_ctrl_isr for command A -> fired and executed
	atomic_set(&dsi_ctrl->dma_irq_trig, 1);

wait_for_done for command A -> returns early as
	dsi_ctrl->dma_irq_trig is 1

ASYNC Command B -> triggered

wait_for_done for command B -> waiting for cmd_dma_done

dsi_ctrl_isr for command A -> executes
	complete_all(&dsi_ctrl->irq_info.cmd_dma_done);

wait_for_done for command B -> returns success incorrectly based on
	complete_all of previous command isr and disable_status_interrupt()
	is not called.

This leads to refcount of dma_done going wrong and dsi_ctrl_isr is not
enabled on suspend resume.

To fix this issue, mark command transfer successful only based on
complete_all(cmd_dma_done). This way disable_status_interrupt() will be
always called either from dsi_ctrl_isr or wait_for_done().

Change-Id: I0379ea7ff82a1e077b95f6996d11d1722de00936
Signed-off-by: Ritesh Kumar <riteshk@codeaurora.org>

parent 7c9c407f

msm/dsi/dsi_ctrl.c

+1 −8

Original line number	Diff line number	Diff line
		@@ -390,13 +390,6 @@ static void dsi_ctrl_dma_cmd_wait_for_done(struct work_struct *work)
		dsi_hw_ops = dsi_ctrl->hw.ops;
		SDE_EVT32(dsi_ctrl->cell_index, SDE_EVTLOG_FUNC_ENTRY);

		/*
		* This atomic state will be set if ISR has been triggered,
		* so the wait is not needed.
		*/
		if (atomic_read(&dsi_ctrl->dma_irq_trig))
		goto done;

		ret = wait_for_completion_timeout(
		&dsi_ctrl->irq_info.cmd_dma_done,
		msecs_to_jiffies(DSI_CTRL_TX_TO_MS));
		@@ -416,8 +409,8 @@ static void dsi_ctrl_dma_cmd_wait_for_done(struct work_struct *work)
		DSI_SINT_CMD_MODE_DMA_DONE);
		}

		done:
		dsi_ctrl->dma_wait_queued = false;
		SDE_EVT32(dsi_ctrl->cell_index, SDE_EVTLOG_FUNC_EXIT);
		}

		static int dsi_ctrl_check_state(struct dsi_ctrl *dsi_ctrl,