Re: [PATCH v2] drm/xe/lrc: Restore CTX_CS_INDIRECT_CTX_OFFSET programming for ADL

[Andi Shyti]

Hi Helen,

On Wed, Sep 30, 2026 at 02:04:30PM -0300, Helen Koike wrote:
> CTX_CS_INDIRECT_CTX_OFFSET default value is not retrieved from the GPU
> by inhibit+context save mechanism since it is not part of the Engine
> Context. Thus, at restore, 0x0 is programed back to the GPU, which is

/programed/programmed/

> an invalid value according to the PRM.

...

>  	/*
>  	 * Enable INDIRECT_CTX leaving INDIRECT_CTX_OFFSET at its default: it
> -	 * varies per engine class, but the default is good enough
> +	 * varies per engine class, but the default is good enough, except on
> +	 * Alder Lake.
>  	 */
>  	xe_lrc_write_ctx_reg(lrc,
>  			     CTX_CS_INDIRECT_CTX,
>  			     (xe_bo_ggtt_addr(lrc->bo) + state.offset) |
>  			     /* Size in CLs. */
>  			     (state.written * sizeof(u32) / 64));
> +	if (GRAPHICS_VER(lrc_to_xe(lrc)) < 20)

Are you assuming that only Alder Lake is xe < 20?

As you are restoring the original code for render and compute,
would it make sense also add a check for class being
XE_EGINE_CLASS_RENDER || XE_ENGINE_CLASS_COMPUTE?

Andi

> +		xe_lrc_write_ctx_reg(lrc,
> +				     CTX_CS_INDIRECT_CTX_OFFSET,
> +				     CTX_INDIRECT_CTX_OFFSET_DEFAULT);
>  
>  	return 0;
>  }
> -- 
> 2.54.0
>