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| author | Logan Gunthorpe <logang@deltatee.com> | 2017-12-06 02:30:51 +0300 |
|---|---|---|
| committer | Jyri Sarha <jsarha@ti.com> | 2017-12-18 14:24:29 +0300 |
| commit | 4e5ca2d930aa8714400aedf4bf1dc959cb04280f (patch) | |
| tree | 6e206656e47f14f6135f0b356a4c066420683161 /drivers/gpu/drm/tilcdc | |
| parent | 9428088c90b6f7d5edd2a1b0d742c75339b36f6e (diff) | |
| download | linux-4e5ca2d930aa8714400aedf4bf1dc959cb04280f.tar.xz | |
drm/tilcdc: ensure nonatomic iowrite64 is not used
Add a check to ensure iowrite64 is only used if it is atomic.
It was decided in [1] that the tilcdc driver should not be using an
atomic operation (so it was left out of this patchset). However, it turns
out that through the drm code, a nonatomic header is actually included:
include/linux/io-64-nonatomic-lo-hi.h
is included from include/drm/drm_os_linux.h:9:0,
from include/drm/drmP.h:74,
from include/drm/drm_modeset_helper.h:26,
from include/drm/drm_atomic_helper.h:33,
from drivers/gpu/drm/tilcdc/tilcdc_crtc.c:19:
And thus, without this change, this patchset would inadvertantly
change the behaviour of the tilcdc driver.
[1] lkml.kernel.org/r/CAK8P3a2HhO_zCnsTzq7hmWSz5La5Thu19FWZpun16iMnyyNreQ@mail.gmail.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Diffstat (limited to 'drivers/gpu/drm/tilcdc')
| -rw-r--r-- | drivers/gpu/drm/tilcdc/tilcdc_regs.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h index 9d528c0a67a4..5048ebb86835 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h @@ -133,7 +133,7 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data) struct tilcdc_drm_private *priv = dev->dev_private; volatile void __iomem *addr = priv->mmio + reg; -#ifdef iowrite64 +#if defined(iowrite64) && !defined(iowrite64_is_nonatomic) iowrite64(data, addr); #else __iowmb(); |