| Message ID | 20171205233058.5365-2-logang@deltatee.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
On 12/06/17 01:30, Logan Gunthorpe wrote: > 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> I guess it is about time for me to pick this up for the next pull request. Thanks, Jyri > --- > 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(); >
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();
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(-)