leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

gpu: host1x: Increase maximum DMA segment size

Browse Source 
Recent versions of the DMA API debug code have started to warn about
violations of the maximum DMA segment size. This is because the segment
size defaults to 64 KiB, which can easily be exceeded in large buffer
allocations such as used in DRM/KMS for framebuffers.

Technically the Tegra SMMU and ARM SMMU don't have a maximum segment
size (they map individual pages irrespective of whether they are
contiguous or not), so the choice of 4 MiB is a bit arbitrary here. The
maximum segment size is a 32-bit unsigned integer, though, so we can't
set it to the correct maximum size, which would be the size of the
aperture.

Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Thierry Reding 2019-06-05 10:46:05 +02:00
parent 4bb923e807
commit 1e390478cf
2 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/gpu/host1x/bus.c
View File

@ -425,6 +425,9 @@ static int host1x_device_add(struct host1x *host1x,
of_dma_configure(&device->dev, host1x->dev->of_node, true);
device->dev.dma_parms = &device->dma_parms;
dma_set_max_seg_size(&device->dev, SZ_4M);
err = host1x_device_parse_dt(device, driver);
if (err < 0) {
kfree(device);

2
include/linux/host1x.h
View File

@ -310,6 +310,8 @@ struct host1x_device {
struct list_head clients;
bool registered;
struct device_dma_parameters dma_parms;
};
static inline struct host1x_device *to_host1x_device(struct device *dev)