Re: [PATCH v4 3/4] drm/radeon: Raise msi_addr_mask to dma_bits

["Christian König" <christian.koenig@amd.com>]

On 1/29/26 02:56, Vivian Wang wrote:
> The code was originally written using no_64bit_msi, which restricts the
> device to 32-bit MSI addresses.
> 
> Since msi_addr_mask is introduced, use DMA_BIT_MASK(dma_bits) instead of
> DMA_BIT_MASK(32) here for msi_addr_mask, describing the restriction more
> precisely and allowing these devices to work on platforms with MSI
> doorbell address above the 32-bit limit, as long as it is within the
> hardware's addressable range.
> 
> Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>

Reviewed-by: Christian König <christian.koenig@amd.com>

> 
> ---
> v4: Patch message rewording for more consistency
> ---
>  drivers/gpu/drm/radeon/radeon_device.c  |  1 +
>  drivers/gpu/drm/radeon/radeon_irq_kms.c | 10 ----------
>  2 files changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
> index 60afaa8e56b4..5faae0361361 100644
> --- a/drivers/gpu/drm/radeon/radeon_device.c
> +++ b/drivers/gpu/drm/radeon/radeon_device.c
> @@ -1374,6 +1374,7 @@ int radeon_device_init(struct radeon_device *rdev,
>  		pr_warn("radeon: No suitable DMA available\n");
>  		return r;
>  	}
> +	rdev->pdev->msi_addr_mask = DMA_BIT_MASK(dma_bits);
>  	rdev->need_swiotlb = drm_need_swiotlb(dma_bits);
>  
>  	/* Registers mapping */
> diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> index d550554a6f3f..839d619e5602 100644
> --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
> +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> @@ -245,16 +245,6 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
>  	if (rdev->flags & RADEON_IS_AGP)
>  		return false;
>  
> -	/*
> -	 * Older chips have a HW limitation, they can only generate 40 bits
> -	 * of address for "64-bit" MSIs which breaks on some platforms, notably
> -	 * IBM POWER servers, so we limit them
> -	 */
> -	if (rdev->family < CHIP_BONAIRE) {
> -		dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n");
> -		rdev->pdev->msi_addr_mask = DMA_BIT_MASK(32);
> -	}
> -
>  	/* force MSI on */
>  	if (radeon_msi == 1)
>  		return true;
>