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Commit c6e8cab4 authored by Shashank Babu Chinta Venkata's avatar Shashank Babu Chinta Venkata
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drm/msm/dsi-staging: handle spurious error interrupts 



DSI controller can trigger spurious error interrupts
during ESD attack scenarios. Add a check for such spurious
interrupts during error handling.

Change-Id: Iab86e34a7d94991de5c2ad1c62404f1dee1c81b6
Signed-off-by: default avatarShashank Babu Chinta Venkata <sbchin@codeaurora.org>
parent 045b32a6

drivers/gpu/drm/msm/dsi-staging/dsi_ctrl.c

+42 −0
Original line number Diff line number Diff line
@@ -2166,6 +2166,35 @@ int dsi_ctrl_phy_reset_config(struct dsi_ctrl *dsi_ctrl, bool enable) 
	return 0;

}



static bool dsi_ctrl_check_for_spurious_error_interrupts(

					struct dsi_ctrl *dsi_ctrl)

{

	const unsigned long intr_check_interval = msecs_to_jiffies(1000);

	const unsigned int interrupt_threshold = 15;

	unsigned long jiffies_now = jiffies;



	if (!dsi_ctrl) {

		pr_err("Invalid DSI controller structure\n");

		return false;

	}



	if (dsi_ctrl->jiffies_start == 0)

		dsi_ctrl->jiffies_start = jiffies;



	dsi_ctrl->error_interrupt_count++;



	if ((jiffies_now - dsi_ctrl->jiffies_start) < intr_check_interval) {

		if (dsi_ctrl->error_interrupt_count > interrupt_threshold) {

			pr_warn("Detected spurious interrupts on dsi ctrl\n");

			return true;

		}

	} else {

		dsi_ctrl->jiffies_start = jiffies;

		dsi_ctrl->error_interrupt_count = 1;

	}

	return false;

}



static void dsi_ctrl_handle_error_status(struct dsi_ctrl *dsi_ctrl,

				unsigned long int error)

{
@@ -2237,6 +2266,19 @@ static void dsi_ctrl_handle_error_status(struct dsi_ctrl *dsi_ctrl, 
	if (error & 0xF)

		pr_err("ack error: 0x%lx\n", error);



	/*

	 * DSI Phy can go into bad state during ESD influence. This can

	 * manifest as various types of spurious error interrupts on

	 * DSI controller. This check will allow us to handle afore mentioned

	 * case and prevent us from re enabling interrupts until a full ESD

	 * recovery is completed.

	 */

	if (dsi_ctrl_check_for_spurious_error_interrupts(dsi_ctrl) &&

				dsi_ctrl->esd_check_underway) {

		dsi_ctrl->hw.ops.soft_reset(&dsi_ctrl->hw);

		return;

	}



	/* enable back DSI interrupts */

	if (dsi_ctrl->hw.ops.error_intr_ctrl)

		dsi_ctrl->hw.ops.error_intr_ctrl(&dsi_ctrl->hw, true);

drivers/gpu/drm/msm/dsi-staging/dsi_ctrl.h

+4 −0
Original line number Diff line number Diff line
@@ -259,6 +259,10 @@ struct dsi_ctrl { 
	bool misr_enable;

	u32 misr_cache;



	/* Check for spurious interrupts */

	unsigned long jiffies_start;

	unsigned int error_interrupt_count;



	bool phy_isolation_enabled;

	bool null_insertion_enabled;

	bool modeupdated;