Re: [Intel-xe] [PATCH v2 4/8] drm/xe: Fix xe_mmio_rmw32 operation

[Maarten Lankhorst <maarten.lankhorst@linux.intel.com>]

Hey,

I thought this was on purpose, and xe_mmio_rmw32 specified which parts 
to keep,

as opposed to i915 which set a clear mask.

If this was not, can you also fix display/xe_de.h to no longer invert?

Otherwise, you break the entirety of display.

~Maarten

On 2023-04-13 00:52, Matt Roper wrote:
> xe_mmio_rmw32 was failing to invert the passed in mask, resulting in a
> register updated that wasn't the expected RMW operation.  Fortunately
> the impact of this mistake was limited, since xe_mmio_rmw32() is only
> used in two places to unmask certain GuC-related interrupts.
>
> Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_mmio.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_mmio.h b/drivers/gpu/drm/xe/xe_mmio.h
> index 388a633b438b..a3b7f9f5db67 100644
> --- a/drivers/gpu/drm/xe/xe_mmio.h
> +++ b/drivers/gpu/drm/xe/xe_mmio.h
> @@ -40,7 +40,7 @@ static inline u32 xe_mmio_rmw32(struct xe_gt *gt, u32 reg, u32 mask,
>   	u32 old, reg_val;
>   
>   	old = xe_mmio_read32(gt, reg);
> -	reg_val = (old & mask) | val;
> +	reg_val = (old & ~mask) | val;
>   	xe_mmio_write32(gt, reg, reg_val);
>   
>   	return old;