[Intel-gfx] [PATCH] drm/i915/gt: Clear the whole first page of LRC on gen9

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Try clearing the whole first page of the LRC on gen9, just in case HW

First page of LRC is a bit misleading as this is first page of
LRC registers and techincally first page of LRC would be hwsp?

So,

s/LRC/LRC register state

> tries peeking at the poisoned data.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_lrc.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 2d6b41e66b16..bf0c5a998428 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -549,7 +549,7 @@ static void set_offsets(u32 *regs,
>  	}
>  
>  	if (clear) {
> -		u8 count = *++data;
> +		unsigned int count = *++data * 16u;

Nitpick: const 

>  
>  		/* Clear past the tail for HW access */
>  		GEM_BUG_ON(dword_in_page(regs) > count);

You might want to add also check that you dont write past page.
As this seems to be always confined inside a page.

No other complaints, and above are minor so

Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>

> @@ -594,7 +594,7 @@ static const u8 gen8_xcs_offsets[] = {
>  	REG16(0x200),
>  	REG(0x028),
>  
> -	END(80)
> +	END(5)
>  };
>  
>  static const u8 gen9_xcs_offsets[] = {
> @@ -678,7 +678,7 @@ static const u8 gen9_xcs_offsets[] = {
>  	REG16(0x67c),
>  	REG(0x068),
>  
> -	END(176)
> +	END(64)
>  };
>  
>  static const u8 gen12_xcs_offsets[] = {
> @@ -710,7 +710,7 @@ static const u8 gen12_xcs_offsets[] = {
>  	REG16(0x274),
>  	REG16(0x270),
>  
> -	END(80)
> +	END(5)
>  };
>  
>  static const u8 gen8_rcs_offsets[] = {
> @@ -747,7 +747,7 @@ static const u8 gen8_rcs_offsets[] = {
>  	LRI(1, 0),
>  	REG(0x0c8),
>  
> -	END(80)
> +	END(5)
>  };
>  
>  static const u8 gen9_rcs_offsets[] = {
> @@ -831,7 +831,7 @@ static const u8 gen9_rcs_offsets[] = {
>  	REG16(0x67c),
>  	REG(0x68),
>  
> -	END(176)
> +	END(64)
>  };
>  
>  static const u8 gen11_rcs_offsets[] = {
> @@ -872,7 +872,7 @@ static const u8 gen11_rcs_offsets[] = {
>  	LRI(1, 0),
>  	REG(0x0c8),
>  
> -	END(80)
> +	END(5)
>  };
>  
>  static const u8 gen12_rcs_offsets[] = {
> @@ -913,7 +913,7 @@ static const u8 gen12_rcs_offsets[] = {
>  	LRI(1, 0),
>  	REG(0x0c8),
>  
> -	END(80)
> +	END(5)
>  };
>  
>  #undef END
> -- 
> 2.25.0