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From: Petr Cvek <petr.cvek@tul.cz>
To: linux-arm-kernel@lists.infradead.org
Subject: [BUG, RFC] Different bitfields in documentation and driver
Date: Fri, 07 Aug 2015 19:14:47 +0000	[thread overview]
Message-ID: <55C503A7.6020304@tul.cz> (raw)

Hello,
It seems that PXA2xx framebuffer has switched bitfields in nonstd definition (when using overlay).

This:

	http://lxr.free-electrons.com/source/drivers/video/fbdev/pxafb.h#L80

versus this:

	http://lxr.free-electrons.com/source/Documentation/fb/pxafb.txt#L128

Should be this changed in documentation or in driver? I was able to find only one use (in form of little outdated mplayer patch) and it fills both bitfields with zero (so potential change in driver will not break it).

P.S. Lack of overlay2's use is probably caused by errata "E24: LCD: Enabling Overlay 2 for YUV420 hangs LCD controller.", which is not workarounded in this driver. It should be mentioned in documentation and/or code, because the only way to start the LCD again is a full PXA SoC reset.

Petr Cvek

WARNING: multiple messages have this Message-ID (diff)
From: petr.cvek@tul.cz (Petr Cvek)
To: linux-arm-kernel@lists.infradead.org
Subject: [BUG, RFC] Different bitfields in documentation and driver
Date: Fri, 07 Aug 2015 21:14:47 +0200	[thread overview]
Message-ID: <55C503A7.6020304@tul.cz> (raw)

Hello,
It seems that PXA2xx framebuffer has switched bitfields in nonstd definition (when using overlay).

This:

	http://lxr.free-electrons.com/source/drivers/video/fbdev/pxafb.h#L80

versus this:

	http://lxr.free-electrons.com/source/Documentation/fb/pxafb.txt#L128

Should be this changed in documentation or in driver? I was able to find only one use (in form of little outdated mplayer patch) and it fills both bitfields with zero (so potential change in driver will not break it).

P.S. Lack of overlay2's use is probably caused by errata "E24: LCD: Enabling Overlay 2 for YUV420 hangs LCD controller.", which is not workarounded in this driver. It should be mentioned in documentation and/or code, because the only way to start the LCD again is a full PXA SoC reset.

Petr Cvek

             reply	other threads:[~2015-08-07 19:14 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-07 19:14 Petr Cvek [this message]
2015-08-07 19:14 ` [BUG, RFC] Different bitfields in documentation and driver Petr Cvek
2015-08-08 16:56 ` Robert Jarzmik
2015-08-08 16:56   ` Robert Jarzmik
2015-08-08 17:41   ` Petr Cvek
2015-08-08 17:41     ` Petr Cvek

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