Messages in this thread Patch in this message | | | From | Logan Gunthorpe <> | Date | Wed, 3 Jan 2018 11:06:11 -0700 | Subject | [PATCH v9 1/8] drm/tilcdc: ensure nonatomic iowrite64 is not used |
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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> --- drivers/gpu/drm/tilcdc/tilcdc_regs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
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(); -- 2.11.0
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