| Message ID | 20170622164817.25515-7-logang@deltatee.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/22/17 19:48, Logan Gunthorpe wrote: > Now that we can expect iowrite64 to always exist the hack is no longer > necessary so we just call iowrite64 directly. > > Signed-off-by: Logan Gunthorpe <logang@deltatee.com> > Cc: Jyri Sarha <jsarha@ti.com> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> > Cc: David Airlie <airlied@linux.ie> Acked-by: Jyri Sarha <jsarha@ti.com> And thanks! > --- > drivers/gpu/drm/tilcdc/tilcdc_regs.h | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h > index e9ce725698a9..0b901405f30a 100644 > --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h > +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h > @@ -133,13 +133,7 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data) > struct tilcdc_drm_private *priv = dev->dev_private; > void __iomem *addr = priv->mmio + reg; > > -#ifdef iowrite64 > iowrite64(data, addr); > -#else > - __iowmb(); > - /* This compiles to strd (=64-bit write) on ARM7 */ > - *(u64 __force *)addr = __cpu_to_le64(data); > -#endif > } > > static inline u32 tilcdc_read(struct drm_device *dev, u32 reg) >
Hi Jyri, Thanks for the ack. However, I'm reworking this patch set to use the include/linux/io-64-nonatomic* headers which will explicitly devolve into two 32-bit transfers. It's not clear whether this is appropriate for the tilcdc driver as it was never setup to use 32-bit transfers (unlike the others I had patched). If you think it's ok, I can still patch this driver to use the non-atomic headers. Otherwise I can leave it out. Please let me know. Thanks, Logan On 26/06/17 02:55 AM, Jyri Sarha wrote: > Acked-by: Jyri Sarha <jsarha@ti.com> > > And thanks! > >> --- >> drivers/gpu/drm/tilcdc/tilcdc_regs.h | 6 ------ >> 1 file changed, 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h >> index e9ce725698a9..0b901405f30a 100644 >> --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h >> +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h >> @@ -133,13 +133,7 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data) >> struct tilcdc_drm_private *priv = dev->dev_private; >> void __iomem *addr = priv->mmio + reg; >> >> -#ifdef iowrite64 >> iowrite64(data, addr); >> -#else >> - __iowmb(); >> - /* This compiles to strd (=64-bit write) on ARM7 */ >> - *(u64 __force *)addr = __cpu_to_le64(data); >> -#endif >> } >> >> static inline u32 tilcdc_read(struct drm_device *dev, u32 reg) >> >
On Mon, Jun 26, 2017 at 6:26 PM, Logan Gunthorpe <logang@deltatee.com> wrote: > Hi Jyri, > > Thanks for the ack. However, I'm reworking this patch set to use the > include/linux/io-64-nonatomic* headers which will explicitly devolve > into two 32-bit transfers. It's not clear whether this is appropriate > for the tilcdc driver as it was never setup to use 32-bit transfers > (unlike the others I had patched). > > If you think it's ok, I can still patch this driver to use the > non-atomic headers. Otherwise I can leave it out. Please let me know. You'd have to first figure out whether this device is of the lo-hi or the hi-lo variant, or doesn't allow the I/O to be split at all. Note that we could theoretically define ARM to use strd/ldrd for writeq/readq, but I would expect that to be wrong with many other devices that can use the existing io-64-nonatomic headers. The comment in set_scanout() suggests that we actually do rely on the write64 to be atomic, so we probably don't want to change this driver. Arnd
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h index e9ce725698a9..0b901405f30a 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h @@ -133,13 +133,7 @@ static inline void tilcdc_write64(struct drm_device *dev, u32 reg, u64 data) struct tilcdc_drm_private *priv = dev->dev_private; void __iomem *addr = priv->mmio + reg; -#ifdef iowrite64 iowrite64(data, addr); -#else - __iowmb(); - /* This compiles to strd (=64-bit write) on ARM7 */ - *(u64 __force *)addr = __cpu_to_le64(data); -#endif } static inline u32 tilcdc_read(struct drm_device *dev, u32 reg)
Now that we can expect iowrite64 to always exist the hack is no longer necessary so we just call iowrite64 directly. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Cc: Jyri Sarha <jsarha@ti.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: David Airlie <airlied@linux.ie> --- drivers/gpu/drm/tilcdc/tilcdc_regs.h | 6 ------ 1 file changed, 6 deletions(-)