On Mon, Mar 26, 2018 at 04:44:14PM +0200, Emil Goode wrote:
> The compiler is complaining with the following errors:
>
> drivers/gpu/host1x/cdma.c:94:48: error:
> passing argument 3 of ‘dma_alloc_wc’ from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>
> drivers/gpu/host1x/cdma.c:113:48: error:
> passing argument 3 of ‘dma_alloc_wc’ from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>
> The expected pointer type of the third argument to dma_alloc_wc() is
> dma_addr_t but phys_addr_t is passed. Fix this by adding casts to the
> expected pointer type.
>
> Signed-off-by: Emil Goode <emil.fsw@xxxxxxxx>
> ---
> drivers/gpu/host1x/cdma.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c
> index 28541b280739..5e8b321a751e 100644
> --- a/drivers/gpu/host1x/cdma.c
> +++ b/drivers/gpu/host1x/cdma.c
> @@ -91,8 +91,8 @@ static int host1x_pushbuffer_init(struct push_buffer *pb)
>
> size = iova_align(&host1x->iova, size);
>
> - pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
> - GFP_KERNEL);
> + pb->mapped = dma_alloc_wc(host1x->dev, size,
> + (dma_addr_t *)&pb->phys, GFP_KERNEL);
> if (!pb->mapped)
> return -ENOMEM;
>
> @@ -110,8 +110,8 @@ static int host1x_pushbuffer_init(struct push_buffer *pb)
> if (err)
> goto iommu_free_iova;
> } else {
> - pb->mapped = dma_alloc_wc(host1x->dev, size, &pb->phys,
> - GFP_KERNEL);
> + pb->mapped = dma_alloc_wc(host1x->dev, size,
> + (dma_addr_t *)&pb->phys, GFP_KERNEL);
> if (!pb->mapped)
> return -ENOMEM;
>
This doesn't seem right. There's no guarantee that phys_addr_t and
dma_addr_t will be compatible, so the above isn't always correct. Also,
I don't see a need for pb->phys to ever be phys_addr_t. It's allocated
through dma_alloc_wc() exclusively, so it should just be dma_addr_t.
Note that the !pb->phys check in host1x_pushbuffer_destroy() becomes
technically wrong if pb->phys is dma_addr_t (0 is a perfectly valid
value for dma_addr_t), so make sure to flip that to !pb->mapped instead.
pb->mapped and pb->phys are always set in tandem, and checking mapped
for non-NULL is the right check to test whether the pair is valid or
not.
Thierry
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