Am 29.08.2017 um 14:43 schrieb Tom St Denis:
> Allows writing data to vram via debugfs.
>
> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 41 ++++++++++++++++++++++++++++++++-
> 1 file changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index c97a99427eea..cdc96d027707 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1671,10 +1671,49 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
> return result;
> }
>
> +static ssize_t amdgpu_ttm_vram_write(struct file *f, const char __user *buf,
> + size_t size, loff_t *pos)
> +{
> + struct amdgpu_device *adev = file_inode(f)->i_private;
> + ssize_t result = 0;
> + int r;
> +
> + if (size & 0x3 || *pos & 0x3)
> + return -EINVAL;
> +
> + if (*pos >= adev->mc.mc_vram_size)
> + return -ENXIO;
> +
> + while (size) {
> + unsigned long flags;
> + uint32_t value;
> +
> + if (*pos >= adev->mc.mc_vram_size)
> + return result;
> +
> + spin_lock_irqsave(&adev->mmio_idx_lock, flags);
> + WREG32(mmMM_INDEX, ((uint32_t)*pos) | 0x80000000);
> + WREG32(mmMM_INDEX_HI, *pos >> 31);
> + r = get_user(value, (uint32_t *)buf);
Don't call get_user() while holding a spin.
> + if (r)
> + return r;
You forget to unlock the spin.
Regards,
Christian.
> + WREG32(mmMM_DATA, value);
> + spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
> +
> + result += 4;
> + buf += 4;
> + *pos += 4;
> + size -= 4;
> + }
> +
> + return result;
> +}
> +
> static const struct file_operations amdgpu_ttm_vram_fops = {
> .owner = THIS_MODULE,
> .read = amdgpu_ttm_vram_read,
> - .llseek = default_llseek
> + .write = amdgpu_ttm_vram_write,
> + .llseek = default_llseek,
> };
>
> #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
