Commit Graph

8 Commits

Author SHA1 Message Date
Arnd Bergmann
287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -07:00
Sushaanth Srirangapathi
713fced8d1 fbdev: da8xx-fb: fix videomodes of lcd panels
Commit 028cd86b79 ("video: da8xx-fb: fix the polarities of the
hsync/vsync pulse") fixes polarities of HSYNC/VSYNC pulse but
forgot to update known_lcd_panels[] which had sync values
according to old logic. This breaks LCD at least on DA850 EVM.

This patch fixes this issue and I have tested this for panel
"Sharp_LK043T1DG01" using DA850 EVM board.

Fixes: 028cd86b79 ("video: da8xx-fb: fix the polarities of the hsync/vsync pulse")
Signed-off-by: Sushaanth Srirangapathi <sushaanth.s@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2016-02-29 18:29:52 +02:00
Arnd Bergmann
ef88ee4e2c fbdev: da8xx-fb: remove incorrect type cast
The probe function correct passes a dma_addr_t pointer into
dma_alloc_coherent(), but has a cast to resource_size_t, which
might be different from dma_addr_t:

drivers/video/fbdev/da8xx-fb.c: In function 'fb_probe':
drivers/video/fbdev/da8xx-fb.c:1431:10: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]

This removes the cast, which avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2016-01-29 13:37:42 +02:00
Wolfram Sang
6a732becfd video: fbdev: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:51 +02:00
Ian Abbott
4d4e2c003b video: da8xx-fb: preserve display width when changing HSYNC
When looking at this driver for a client, I noticed the code that
configures the HSYNC pulse clobbers the display width in the same
register.  It only preserves the MS part of the width in bit 3 and zeros
the LS part of the width in bits 9 to 4.  This doesn't matter during
initialization as the width is configured afterwards, but subsequent use
of the FBIPUT_HSYNC ioctl would clobber the width.

Preserve bits 9 to 0 of LCD_RASTER_TIMING_0_REG when configuring the
horizontal sync.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2014-08-26 15:36:51 +03:00
Joe Perches
0d0b4b4d1d fbdev: da8xx-fb: Use dma_zalloc_coherent
Use the zeroing function instead of dma_alloc_coherent & memset(,0,)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2014-07-01 13:32:31 +03:00
Jon Ringle
f474f0e1fb video: da8xx-fb: Add support for Densitron 84-0023-001T
Signed-off-by: Jon Ringle <jringle@gridpoint.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2014-04-22 08:51:27 +03:00
Tomi Valkeinen
f7018c2135 video: move fbdev to drivers/video/fbdev
The drivers/video directory is a mess. It contains generic video related
files, directories for backlight, console, linux logo, lots of fbdev
device drivers, fbdev framework files.

Make some order into the chaos by creating drivers/video/fbdev
directory, and move all fbdev related files there.

No functionality is changed, although I guess it is possible that some
subtle Makefile build order related issue could be created by this
patch.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-04-17 08:10:19 +03:00