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* [PATCH] drm/dp: only accept valid DP_TRAINING_AUX_RD_INTERVAL values
@ 2018-03-02 22:25 matthew.s.atwood
  2018-03-02 23:22 ` Rodrigo Vivi
                   ` (12 more replies)
  0 siblings, 13 replies; 36+ messages in thread
From: matthew.s.atwood @ 2018-03-02 22:25 UTC (permalink / raw)
  To: dri-devel; +Cc: Matt Atwood

From: Matt Atwood <matthew.s.atwood@intel.com>

For panels that do not follow Display Port specifications mask off invalid
values for DP_TRAINING_AUX_RD_INTERVAL. Specification lists acceptable
values 0-4 all other values are reserved and bit 7 of DPCD 0x0000e
describes another feature. Currently the code uses all of DPCD 0x0000e and
can cause max wait for 1024 ms instead of 16 ms as specified table 2-158.
This address is read for both clock recovery and channel equalization.

Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 4 ++--
 include/drm/drm_dp_helper.h     | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index adf79be..a7e9b75 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -122,7 +122,7 @@ void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 	if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0)
 		udelay(100);
 	else
-		mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4);
+		mdelay((dpcd[DP_TRAINING_AUX_RD_INTERVAL] & DP_TRAINING_AUX_RD_MASK) * 4);
 }
 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
 
@@ -130,7 +130,7 @@ void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) {
 	if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0)
 		udelay(400);
 	else
-		mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4);
+		mdelay((dpcd[DP_TRAINING_AUX_RD_INTERVAL] & DP_TRAINING_AUX_RD_MASK) * 4);
 }
 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
 
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index da58a42..77ba003 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -118,6 +118,7 @@
 # define DP_DPCD_DISPLAY_CONTROL_CAPABLE     (1 << 3) /* edp v1.2 or higher */
 
 #define DP_TRAINING_AUX_RD_INTERVAL         0x00e   /* XXX 1.2? */
+# define DP_TRAINING_AUX_RD_MASK            0x7     /* 1.4 */
 
 #define DP_ADAPTER_CAP			    0x00f   /* 1.2 */
 # define DP_FORCE_LOAD_SENSE_CAP	    (1 << 0)
-- 
2.7.4

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^ permalink raw reply related	[flat|nested] 36+ messages in thread

end of thread, other threads:[~2018-03-17  3:34 UTC | newest]

Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-03-02 22:25 [PATCH] drm/dp: only accept valid DP_TRAINING_AUX_RD_INTERVAL values matthew.s.atwood
2018-03-02 23:22 ` Rodrigo Vivi
2018-03-04 10:03   ` Jani Nikula
2018-03-02 23:24 ` Manasi Navare
2018-03-03  7:34 ` Benson Leung
2018-03-04 10:02 ` Jani Nikula
2018-03-06 18:37 ` [PATCH] drm/dp: Correctly mask DP_TRAINING_AUX_RD_INTERVAL values for DP 1.4 matthew.s.atwood
2018-03-06 19:21   ` Benson Leung
2018-03-06 23:24   ` Rodrigo Vivi
2018-03-07  0:24     ` Pandiyan, Dhinakaran
2018-03-07  0:41       ` [Intel-gfx] " Pandiyan, Dhinakaran
2018-03-07  1:36       ` Manasi Navare
2018-03-07  2:13         ` Pandiyan, Dhinakaran
2018-03-07 22:06           ` Rodrigo Vivi
2018-03-07 22:20             ` [Intel-gfx] " Manasi Navare
2018-03-06 20:08 ` ✓ Fi.CI.BAT: success for " Patchwork
2018-03-07  0:43 ` ✓ Fi.CI.IGT: " Patchwork
2018-03-07 23:44 ` [PATCH] " matthew.s.atwood
2018-03-07 23:58   ` Ilia Mirkin
2018-03-08  0:18   ` Manasi Navare
2018-03-08  0:13 ` matthew.s.atwood
2018-03-08  0:36   ` Benson Leung
2018-03-08  0:28 ` matthew.s.atwood
2018-03-08  0:49   ` Benson Leung
2018-03-08  7:22   ` [Intel-gfx] " Jani Nikula
2018-03-09 23:49     ` Atwood, Matthew S
2018-03-12 19:39       ` Rodrigo Vivi
2018-03-14 17:40 ` matthew.s.atwood
2018-03-14 20:22   ` Rodrigo Vivi
2018-03-16 11:47   ` kbuild test robot
2018-03-14 20:20 ` matthew.s.atwood
2018-03-14 20:59   ` Rodrigo Vivi
2018-03-15 21:08 ` matthew.s.atwood
2018-03-16  0:39   ` Rodrigo Vivi
2018-03-16 23:10   ` kbuild test robot
2018-03-17  3:34   ` Benson Leung

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