From e8b2577c5e312d175ed11a35a12346b19059277d Mon Sep 17 00:00:00 2001
From: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Date: Mon, 18 Sep 2017 15:21:39 -0700
Subject: [PATCH] drm/i915/dp: Fix buffer size for sink_irq_esi read
Git-commit: e8b2577c5e312d175ed11a35a12346b19059277d
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900

The buffer size defined is 16 bytes whereas only 14 bytes are read. Add a
macro to avoid this discrepancy.

Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170918222141.4674-3-dhinakaran.pandiyan@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/intel_dp.c |   15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -42,6 +42,7 @@
 #include "i915_drv.h"
 
 #define DP_LINK_CHECK_TIMEOUT	(10 * 1000)
+#define DP_DPRX_ESI_LEN 14
 
 /* Compliance test status bits  */
 #define INTEL_DP_RESOLUTION_SHIFT_MASK	0
@@ -4020,15 +4021,9 @@ intel_dp_get_sink_irq(struct intel_dp *i
 static bool
 intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
 {
-	int ret;
-
-	ret = drm_dp_dpcd_read(&intel_dp->aux,
-					     DP_SINK_COUNT_ESI,
-					     sink_irq_vector, 14);
-	if (ret != 14)
-		return false;
-
-	return true;
+	return drm_dp_dpcd_read(&intel_dp->aux, DP_SINK_COUNT_ESI,
+				sink_irq_vector, DP_DPRX_ESI_LEN) ==
+		DP_DPRX_ESI_LEN;
 }
 
 static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp)
@@ -4228,7 +4223,7 @@ intel_dp_check_mst_status(struct intel_d
 	bool bret;
 
 	if (intel_dp->is_mst) {
-		u8 esi[16] = { 0 };
+		u8 esi[DP_DPRX_ESI_LEN] = { 0 };
 		int ret = 0;
 		int retry;
 		bool handled;