Re: [PATCH] drm/amdgpu: Fix discovery initialization failure during pci rescan

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 01.04.24 um 12:18 schrieb Ma Jun:
> Waiting for system ready to fix the discovery initialization
> failure issue. This failure usually occurs when dGPU is
> removed and then rescanned via command line.
> It's caused by following two errors:
> [1] vram size is 0
> [2] wrong binary signature
>
> Signed-off-by: Ma Jun <Jun.Ma2@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> index 07c5fca06178..ac6b2ae6414c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> @@ -276,7 +276,12 @@ static int amdgpu_discovery_read_binary_from_mem(struct amdgpu_device *adev,
>   			msleep(1);
>   		}
>   	}
> -	vram_size = (uint64_t)RREG32(mmRCC_CONFIG_MEMSIZE) << 20;
> +	for (i = 0; i < 100; i++) {
> +		vram_size = (uint64_t)RREG32(mmRCC_CONFIG_MEMSIZE) << 20;
> +		if (vram_size)
> +			break;
> +		usleep_range(1000, 1100);
> +	}

Nice that we come closer to a solution for this, but that here is really 
hacky.

Do we have any idea why mmRCC_CONFIG_MEMSIZE is zero when we re-scan? Is 
some initialization not completed yet or something like that.

Regards,
Christian.

>   
>   	if (vram_size) {
>   		uint64_t pos = vram_size - DISCOVERY_TMR_OFFSET;
> @@ -371,6 +376,7 @@ static int amdgpu_discovery_init(struct amdgpu_device *adev)
>   {
>   	struct table_info *info;
>   	struct binary_header *bhdr;
> +	int error_count = 0;
>   	uint16_t offset;
>   	uint16_t size;
>   	uint16_t checksum;
> @@ -380,7 +386,7 @@ static int amdgpu_discovery_init(struct amdgpu_device *adev)
>   	adev->mman.discovery_bin = kzalloc(adev->mman.discovery_tmr_size, GFP_KERNEL);
>   	if (!adev->mman.discovery_bin)
>   		return -ENOMEM;
> -
> +retry:
>   	/* Read from file if it is the preferred option */
>   	if (amdgpu_discovery == 2) {
>   		dev_info(adev->dev, "use ip discovery information from file");
> @@ -401,6 +407,10 @@ static int amdgpu_discovery_init(struct amdgpu_device *adev)
>   
>   	/* check the ip discovery binary signature */
>   	if (!amdgpu_discovery_verify_binary_signature(adev->mman.discovery_bin)) {
> +		if (error_count++ < 1) {
> +			msleep(100);
> +			goto retry;
> +		}
>   		dev_err(adev->dev,
>   			"get invalid ip discovery binary signature\n");
>   		r = -EINVAL;
> @@ -515,7 +525,6 @@ static int amdgpu_discovery_init(struct amdgpu_device *adev)
>   	if (0 && offset) {
>   		struct mall_info_header *mhdr =
>   			(struct mall_info_header *)(adev->mman.discovery_bin + offset);
> -
>   		if (le32_to_cpu(mhdr->table_id) != MALL_INFO_TABLE_ID) {
>   			dev_err(adev->dev, "invalid ip discovery mall table id\n");
>   			r = -EINVAL;