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authorLogan Gunthorpe <logang@deltatee.com>2017-12-06 02:30:51 +0300
committerJyri Sarha <jsarha@ti.com>2017-12-18 14:24:29 +0300
commit4e5ca2d930aa8714400aedf4bf1dc959cb04280f (patch)
tree6e206656e47f14f6135f0b356a4c066420683161 /drivers/gpu/drm/tilcdc
parent9428088c90b6f7d5edd2a1b0d742c75339b36f6e (diff)
downloadlinux-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.h2
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();