diff mbox

drm/i915: Correct max delay for HDMI hotplug live status checking

Message ID 9D94B3A055E7584690C06E97E27A67B90B2DA764@PGSMSX101.gar.corp.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gary C Wang Dec. 11, 2015, 7:10 a.m. UTC
I will upload new version of patch for review. Thanks!

-----Original Message-----
From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf Of Wang, Gary C
Sent: Friday, December 11, 2015 2:23 PM
To: Jindal, Sonika <sonika.jindal@intel.com>; intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

No problem. 

Please refer following information.
Lenovo Mode: L246 1xwA (4/30 failed, necessary hot-plug delay: 58/40/60/40ms) Philips Model : HH2AP (9/30 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms) BENQ Model:ET-0035-N (6/30 failed, necessary hot-plug delay: 60/50/50/80/80/40ms) DELL  Model:U2713HM (2/30 failed, necessary hot-plug delay: 58/59ms) HP Model: HP-LP2475w (5/30 failed, necessary hot-plug delay: 70/50/40/60/40ms)

Those test were based on following test-case (test continually with 30 test cycles), 1. HDMI display correctly 2. Un-plug/re-plug HDMI cable 3. Wait for one sec

Thanks for your review!

Gary

-----Original Message-----
From: Jindal, Sonika
Sent: Friday, December 11, 2015 2:18 PM
To: Wang, Gary C <gary.c.wang@intel.com>; intel-gfx@lists.freedesktop.org
Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

Sure.
Can you please also post your findings about different panels taking different time to settle the live status so that we know that this increase in retrials is helping you with multiple monitors?

Regards,
Sonika


-----Original Message-----
From: Wang, Gary C
Sent: Friday, December 11, 2015 11:34 AM
To: Jindal, Sonika <sonika.jindal@intel.com>; intel-gfx@lists.freedesktop.org
Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

Hi Sonika,

Thanks for your comment, and it's more readability on code.

But it only delay 2 integration of each 10ms among checking hot-plug with 3 times. Could I change it to following snippet code to read hotplug_status 4 times at most for 3 integration 10ms delay?

	unsigned int retry = 3;	

	do {
		live_status = intel_digital_port_connected(dev_priv,
				hdmi_to_dig_port(intel_hdmi));
		if (live_status || !retry)
			break;
		mdelay(10);
	} while (retry--);

Thanks!

Gary

-----Original Message-----
From: Jindal, Sonika
Sent: Friday, December 11, 2015 1:05 PM
To: Wang, Gary C <gary.c.wang@intel.com>; intel-gfx@lists.freedesktop.org
Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

How about following instead of two levels of check in the while loop:

unsigned int retry = 3;

do {
	live_status = intel_digital_port_connected(dev_priv,
			hdmi_to_dig_port(intel_hdmi));
	if (live_status)
		break;
	mdelay(10);
} while (--retry);

Regards,
Sonika

-----Original Message-----
From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf Of Wang, Gary C
Sent: Friday, December 11, 2015 7:39 AM
To: intel-gfx@lists.freedesktop.org
Subject: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

The total delay of HDMI hotplug detecting with 30ms should have been split into a resolution of 3 retries of 10ms each, for the worst cases. But it still suffered from only waiting 10ms at most in intel_hdmi_detect(). This patch corrects it by reading hotplug status with 4 times at most for 30ms delay.

Reviewed-by: Cooper Chiou <cooper.chiou@intel.com>
Cc: Gavin Hindman <gavin.hindman@intel.com>
Signed-off-by: Gary Wang <gary.c.wang@intel.com>
---
 drivers/gpu/drm/i915/intel_hdmi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)  mode change 100644 => 100755 drivers/gpu/drm/i915/intel_hdmi.c

--
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx

Comments

Daniel Vetter Dec. 11, 2015, 6:42 p.m. UTC | #1
On Fri, Dec 11, 2015 at 07:10:35AM +0000, Wang, Gary C wrote:
> I will upload new version of patch for review. Thanks!
> 
> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf Of Wang, Gary C
> Sent: Friday, December 11, 2015 2:23 PM
> To: Jindal, Sonika <sonika.jindal@intel.com>; intel-gfx@lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking
> 
> No problem. 
> 
> Please refer following information.
> Lenovo Mode: L246 1xwA (4/30 failed, necessary hot-plug delay: 58/40/60/40ms) Philips Model : HH2AP (9/30 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms) BENQ Model:ET-0035-N (6/30 failed, necessary hot-plug delay: 60/50/50/80/80/40ms) DELL  Model:U2713HM (2/30 failed, necessary hot-plug delay: 58/59ms) HP Model: HP-LP2475w (5/30 failed, necessary hot-plug delay: 70/50/40/60/40ms)
> 
> Those test were based on following test-case (test continually with 30 test cycles), 1. HDMI display correctly 2. Un-plug/re-plug HDMI cable 3. Wait for one sec
> 
> Thanks for your review!
> 
> Gary
> 
> -----Original Message-----
> From: Jindal, Sonika
> Sent: Friday, December 11, 2015 2:18 PM
> To: Wang, Gary C <gary.c.wang@intel.com>; intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking
> 
> Sure.
> Can you please also post your findings about different panels taking different time to settle the live status so that we know that this increase in retrials is helping you with multiple monitors?
> 
> Regards,
> Sonika
> 
> 
> -----Original Message-----
> From: Wang, Gary C
> Sent: Friday, December 11, 2015 11:34 AM
> To: Jindal, Sonika <sonika.jindal@intel.com>; intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking
> 
> Hi Sonika,
> 
> Thanks for your comment, and it's more readability on code.
> 
> But it only delay 2 integration of each 10ms among checking hot-plug with 3 times. Could I change it to following snippet code to read hotplug_status 4 times at most for 3 integration 10ms delay?
> 
> 	unsigned int retry = 3;	
> 
> 	do {
> 		live_status = intel_digital_port_connected(dev_priv,
> 				hdmi_to_dig_port(intel_hdmi));
> 		if (live_status || !retry)
> 			break;
> 		mdelay(10);
> 	} while (retry--);
> 
> Thanks!
> 
> Gary
> 
> -----Original Message-----
> From: Jindal, Sonika
> Sent: Friday, December 11, 2015 1:05 PM
> To: Wang, Gary C <gary.c.wang@intel.com>; intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking
> 
> How about following instead of two levels of check in the while loop:
> 
> unsigned int retry = 3;
> 
> do {
> 	live_status = intel_digital_port_connected(dev_priv,
> 			hdmi_to_dig_port(intel_hdmi));
> 	if (live_status)
> 		break;
> 	mdelay(10);
> } while (--retry);
> 
> Regards,
> Sonika
> 
> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On Behalf Of Wang, Gary C
> Sent: Friday, December 11, 2015 7:39 AM
> To: intel-gfx@lists.freedesktop.org
> Subject: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking
> 
> The total delay of HDMI hotplug detecting with 30ms should have been split into a resolution of 3 retries of 10ms each, for the worst cases. But it still suffered from only waiting 10ms at most in intel_hdmi_detect(). This patch corrects it by reading hotplug status with 4 times at most for 30ms delay.
> 
> Reviewed-by: Cooper Chiou <cooper.chiou@intel.com>
> Cc: Gavin Hindman <gavin.hindman@intel.com>
> Signed-off-by: Gary Wang <gary.c.wang@intel.com>

Can we please have less top-posting when reviewing patches? I can't really
read the above with my bare-knuckles console mail client I use for reading
patch mailing lists ;-)


> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)  mode change 100644 => 100755 drivers/gpu/drm/i915/intel_hdmi.c
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> old mode 100644
> new mode 100755
> index be7fab9..888401b
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1387,16 +1387,19 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
>  	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
>  	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	bool live_status = false;
> -	unsigned int retry = 3;
> +	// read hotplug status 4 times at most for 30ms delay (3 retries of 10ms each)

Please no C++ comments, also your code should be self-explanatory enough
that this is obvious.

> +	unsigned int retry = 4;
>  
>  	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
>  		      connector->base.id, connector->name);
>  
>  	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
>  
> -	while (!live_status && --retry) {
> +	while (!live_status && retry--) {
>  		live_status = intel_digital_port_connected(dev_priv,
>  				hdmi_to_dig_port(intel_hdmi));
> +		if (live_status || !retry)
> +				break;
>  		mdelay(10);

Whiel at it please review my patch to switch this one to an msleep - it's
not nice to kill the battery with a busy loop like this.
-Daniel

>  	}
>  
> --
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Gary C Wang Dec. 14, 2015, 2:30 a.m. UTC | #2
I totally agree on Ville and Daniel's comments and am sorry for incorrect text format of some description.

Following code should be more clear. It only delays 3 times (30ms delay) at most for checking hot-plug status.

-       unsigned int retry = 3;
+       unsigned int retry;

        DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
                      connector->base.id, connector->name);

-       while (!live_status && --retry) {
+       for (retry = 3; retry >= 0; retry--) {
                live_status = intel_digital_port_connected(dev_priv,
                                hdmi_to_dig_port(intel_hdmi));
-               mdelay(10);
+               if (live_status || !retry)
+                               break;
+               msleep(10);
        }

        if (!live_status)


BTW, I list again for hot-plug delay test on my BSW platform. It seems to be not enough with 30ms delay for some old HDMI monitor,


Please refer following information for my BSW platform,
1. Lenovo Mode: L246 1xwA (4/30 failed, necessary hot-plug delay: 58/40/60/40ms) ,
2. Philips Model : HH2AP (9/30 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms) ,
3. BENQ Model:ET-0035-N (6/30 failed, necessary hot-plug delay: 60/50/50/80/80/40ms) ,
4. DELL  Model:U2713HM (2/30 failed, necessary hot-plug delay: 58/59ms) ,
5. HP Model: HP-LP2475w (5/30 failed, necessary hot-plug delay: 70/50/40/60/40ms),


Those test were based on following test-case (test continually with 30 test cycles)
1. HDMI display correctly 
2. Un-plug/re-plug HDMI cable 
3. Wait for one sec


Thanks!

Gary

-----Original Message-----
From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel Vetter
Sent: Saturday, December 12, 2015 2:43 AM
To: Wang, Gary C <gary.c.wang@intel.com>
Cc: Jindal, Sonika <sonika.jindal@intel.com>; intel-gfx@lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI hotplug live status checking

On Fri, Dec 11, 2015 at 07:10:35AM +0000, Wang, Gary C wrote:
> I will upload new version of patch for review. Thanks!
> 
> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On 
> Behalf Of Wang, Gary C
> Sent: Friday, December 11, 2015 2:23 PM
> To: Jindal, Sonika <sonika.jindal@intel.com>; 
> intel-gfx@lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI 
> hotplug live status checking
> 
> No problem. 
> 
> Please refer following information.
> Lenovo Mode: L246 1xwA (4/30 failed, necessary hot-plug delay: 
> 58/40/60/40ms) Philips Model : HH2AP (9/30 failed, necessary hot-plug 
> delay: 80/50/50/60/46/40/58/58/39ms) BENQ Model:ET-0035-N (6/30 
> failed, necessary hot-plug delay: 60/50/50/80/80/40ms) DELL  
> Model:U2713HM (2/30 failed, necessary hot-plug delay: 58/59ms) HP 
> Model: HP-LP2475w (5/30 failed, necessary hot-plug delay: 
> 70/50/40/60/40ms)
> 
> Those test were based on following test-case (test continually with 30 
> test cycles), 1. HDMI display correctly 2. Un-plug/re-plug HDMI cable 
> 3. Wait for one sec
> 
> Thanks for your review!
> 
> Gary
> 
> -----Original Message-----
> From: Jindal, Sonika
> Sent: Friday, December 11, 2015 2:18 PM
> To: Wang, Gary C <gary.c.wang@intel.com>; 
> intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI 
> hotplug live status checking
> 
> Sure.
> Can you please also post your findings about different panels taking different time to settle the live status so that we know that this increase in retrials is helping you with multiple monitors?
> 
> Regards,
> Sonika
> 
> 
> -----Original Message-----
> From: Wang, Gary C
> Sent: Friday, December 11, 2015 11:34 AM
> To: Jindal, Sonika <sonika.jindal@intel.com>; 
> intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI 
> hotplug live status checking
> 
> Hi Sonika,
> 
> Thanks for your comment, and it's more readability on code.
> 
> But it only delay 2 integration of each 10ms among checking hot-plug with 3 times. Could I change it to following snippet code to read hotplug_status 4 times at most for 3 integration 10ms delay?
> 
> 	unsigned int retry = 3;	
> 
> 	do {
> 		live_status = intel_digital_port_connected(dev_priv,
> 				hdmi_to_dig_port(intel_hdmi));
> 		if (live_status || !retry)
> 			break;
> 		mdelay(10);
> 	} while (retry--);
> 
> Thanks!
> 
> Gary
> 
> -----Original Message-----
> From: Jindal, Sonika
> Sent: Friday, December 11, 2015 1:05 PM
> To: Wang, Gary C <gary.c.wang@intel.com>; 
> intel-gfx@lists.freedesktop.org
> Subject: RE: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI 
> hotplug live status checking
> 
> How about following instead of two levels of check in the while loop:
> 
> unsigned int retry = 3;
> 
> do {
> 	live_status = intel_digital_port_connected(dev_priv,
> 			hdmi_to_dig_port(intel_hdmi));
> 	if (live_status)
> 		break;
> 	mdelay(10);
> } while (--retry);
> 
> Regards,
> Sonika
> 
> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-bounces@lists.freedesktop.org] On 
> Behalf Of Wang, Gary C
> Sent: Friday, December 11, 2015 7:39 AM
> To: intel-gfx@lists.freedesktop.org
> Subject: [Intel-gfx] [PATCH] drm/i915: Correct max delay for HDMI 
> hotplug live status checking
> 
> The total delay of HDMI hotplug detecting with 30ms should have been split into a resolution of 3 retries of 10ms each, for the worst cases. But it still suffered from only waiting 10ms at most in intel_hdmi_detect(). This patch corrects it by reading hotplug status with 4 times at most for 30ms delay.
> 
> Reviewed-by: Cooper Chiou <cooper.chiou@intel.com>
> Cc: Gavin Hindman <gavin.hindman@intel.com>
> Signed-off-by: Gary Wang <gary.c.wang@intel.com>

Can we please have less top-posting when reviewing patches? I can't really read the above with my bare-knuckles console mail client I use for reading patch mailing lists ;-)


> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)  mode change 100644 
> => 100755 drivers/gpu/drm/i915/intel_hdmi.c
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c 
> b/drivers/gpu/drm/i915/intel_hdmi.c
> old mode 100644
> new mode 100755
> index be7fab9..888401b
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1387,16 +1387,19 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
>  	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
>  	struct drm_i915_private *dev_priv = to_i915(connector->dev);
>  	bool live_status = false;
> -	unsigned int retry = 3;
> +	// read hotplug status 4 times at most for 30ms delay (3 retries of 
> +10ms each)

Please no C++ comments, also your code should be self-explanatory enough that this is obvious.

> +	unsigned int retry = 4;
>  
>  	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
>  		      connector->base.id, connector->name);
>  
>  	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
>  
> -	while (!live_status && --retry) {
> +	while (!live_status && retry--) {
>  		live_status = intel_digital_port_connected(dev_priv,
>  				hdmi_to_dig_port(intel_hdmi));
> +		if (live_status || !retry)
> +				break;
>  		mdelay(10);

Whiel at it please review my patch to switch this one to an msleep - it's not nice to kill the battery with a busy loop like this.
-Daniel

>  	}
>  
> --
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
old mode 100644
new mode 100755
index be7fab9..888401b
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1387,16 +1387,19 @@  intel_hdmi_detect(struct drm_connector *connector, bool force)
 	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
 	bool live_status = false;
-	unsigned int retry = 3;
+	// read hotplug status 4 times at most for 30ms delay (3 retries of 10ms each)
+	unsigned int retry = 4;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
 
 	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-	while (!live_status && --retry) {
+	while (!live_status && retry--) {
 		live_status = intel_digital_port_connected(dev_priv,
 				hdmi_to_dig_port(intel_hdmi));
+		if (live_status || !retry)
+				break;
 		mdelay(10);
 	}