Re: [PATCH] drm/xe/nvm: fix writable override for CRI

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Jul 08, 2026 at 06:00:17PM +0300, Alexander Usyskin wrote:
> The witable override should be set when FDO_MODE bit is enabled.
> Fix the comparison to distingush this case from legacy systems
> where bit should be disabled to have override.
> 
> Cc: stable@vger.kernel.org
> Fixes: 9dde74fd9e65 ("drm/xe/nvm: enable cri platform")
> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_nvm.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_nvm.c b/drivers/gpu/drm/xe/xe_nvm.c
> index 33487e91f366..d50ee414e83e 100644
> --- a/drivers/gpu/drm/xe/xe_nvm.c
> +++ b/drivers/gpu/drm/xe/xe_nvm.c
> @@ -60,35 +60,39 @@ static bool xe_nvm_writable_override(struct xe_device *xe)
>  	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
>  	bool writable_override;
>  	struct xe_reg reg;
> -	u32 test_bit;
> +	u32 test_bit, test_val;
>  
>  	switch (xe->info.platform) {
>  	case XE_CRESCENTISLAND:
>  		reg = PCODE_SCRATCH(0);
> -		test_bit = FDO_MODE;
> +		test_val = test_bit = FDO_MODE;

-:31: CHECK:MULTIPLE_ASSIGNMENTS: multiple assignments should be avoided
#31: FILE: drivers/gpu/drm/xe/xe_nvm.c:68:
+		test_val = test_bit = FDO_MODE;

total: 0 errors, 0 warnings, 1 checks, 42 lines checked

>  		break;
>  	case XE_BATTLEMAGE:
>  		reg = HECI_FWSTS2(DG2_GSC_HECI2_BASE);
>  		test_bit = HECI_FW_STATUS_2_NVM_ACCESS_MODE;
> +		test_val = 0;
>  		break;
>  	case XE_PVC:
>  		reg = HECI_FWSTS2(PVC_GSC_HECI2_BASE);
>  		test_bit = HECI_FW_STATUS_2_NVM_ACCESS_MODE;
> +		test_val = 0;
>  		break;
>  	case XE_DG2:
>  		reg = HECI_FWSTS2(DG2_GSC_HECI2_BASE);
>  		test_bit = HECI_FW_STATUS_2_NVM_ACCESS_MODE;
> +		test_val = 0;
>  		break;
>  	case XE_DG1:
>  		reg = HECI_FWSTS2(DG1_GSC_HECI2_BASE);
>  		test_bit = HECI_FW_STATUS_2_NVM_ACCESS_MODE;
> +		test_val = 0;
>  		break;
>  	default:
>  		drm_err(&xe->drm, "Unknown platform\n");
>  		return true;
>  	}
>  
> -	writable_override = !(xe_mmio_read32(mmio, reg) & test_bit);
> +	writable_override = (xe_mmio_read32(mmio, reg) & test_bit) == test_val;
>  	if (writable_override)
>  		drm_info(&xe->drm, "NVM access overridden by jumper\n");
>  	return writable_override;
> 
> ---
> base-commit: 8cdeaa50eae8dad34885515f62559ee83e7e8dda
> change-id: 20260708-cri_nvm_fdo_flip-333b545e1dd8
> 
> Best regards,
> -- 
> Alexander Usyskin <alexander.usyskin@intel.com>
>