Re: [PATCH 1/7] drm/tilcdc: don't use volatile with iowrite64

From: Jyri Sarha
Date: Mon Jun 26 2017 - 04:55:03 EST


On 06/22/17 19:48, Logan Gunthorpe wrote:
> This is a prep patch for adding a universal iowrite64.
>
> The patch is to prevent compiler warnings when we add iowrite64 that
> would occur because there is an unnecessary volatile in this driver.
>
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> Cc: Jyri Sarha <jsarha@xxxxxx>
> Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>

Acked-by: Jyri Sarha <jsarha@xxxxxx>

> ---
> drivers/gpu/drm/tilcdc/tilcdc_regs.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_regs.h b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> index 9d528c0a67a4..e9ce725698a9 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_regs.h
> @@ -131,14 +131,14 @@ static inline void tilcdc_write(struct drm_device *dev, u32 reg, u32 data)
> 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;
> + void __iomem *addr = priv->mmio + reg;
>
> #ifdef iowrite64
> iowrite64(data, addr);
> #else
> __iowmb();
> /* This compiles to strd (=64-bit write) on ARM7 */
> - *(volatile u64 __force *)addr = __cpu_to_le64(data);
> + *(u64 __force *)addr = __cpu_to_le64(data);
> #endif
> }
>
>