[Intel-gfx] [PATCH 1/4] drm/i915/selftests: Break out of the lrc layout test after register mismatch

[Tvrtko Ursulin]

On 06/01/2021 12:39, Chris Wilson wrote:
> AFter detecting a register mismatch between the protocontext and the
> image generated by HW, immediately break out of the double loop.
> (Otherwise we end up a second configuing error message.)

s/configuing/confusing/?

No use of dumping all differences? Why it is confusing?

Regards,

Tvrtko

> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/gt/selftest_lrc.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
> index 3485cb7c431d..920979a89413 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
> @@ -164,7 +164,7 @@ static int live_lrc_layout(void *arg)
>   
>   		dw = 0;
>   		do {
> -			u32 lri = hw[dw];
> +			u32 lri = READ_ONCE(hw[dw]);
>   
>   			if (lri == 0) {
>   				dw++;
> @@ -197,9 +197,11 @@ static int live_lrc_layout(void *arg)
>   			dw++;
>   
>   			while (lri) {
> -				if (hw[dw] != lrc[dw]) {
> +				u32 offset = READ_ONCE(hw[dw]);
> +
> +				if (offset != lrc[dw]) {
>   					pr_err("%s: Different registers found at dword %d, expected %x, found %x\n",
> -					       engine->name, dw, hw[dw], lrc[dw]);
> +					       engine->name, dw, offset, lrc[dw]);
>   					err = -EINVAL;
>   					break;
>   				}
> @@ -211,7 +213,7 @@ static int live_lrc_layout(void *arg)
>   				dw += 2;
>   				lri -= 2;
>   			}
> -		} while ((lrc[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
> +		} while (!err && (lrc[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
>   
>   		if (err) {
>   			pr_info("%s: HW register image:\n", engine->name);
>