diff options
author | Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> | 2021-06-04 09:00:11 -0400 |
---|---|---|
committer | Steven Price <steven.price@arm.com> | 2021-06-04 16:16:04 +0100 |
commit | 3e2926f8753dac1ded56c8ef3e91f56ee763dafd (patch) | |
tree | 87dceeacea1e1bae6dafe8aa8a088404446d20d3 /drivers/gpu/drm/panfrost/panfrost_drv.c | |
parent | cb1c81467af355829a4a9d8fa3f92ffab355d93c (diff) |
drm/panfrost: Add AFBC_FEATURES parameter
The value of the AFBC_FEATURES register is required by userspace to
determine AFBC support on Bifrost. A user on our IRC channel (#panfrost)
reported a workload that raised a fault on one system's Mali G31 but
worked flawlessly with another system's Mali G31. We determined the
cause to be missing AFBC support on one vendor's Mali implementation --
it turns out AFBC is optional on Bifrost!
Whether AFBC is supported or not is exposed in the AFBC_FEATURES
register on Bifrost, which reads back as 0 on Midgard. A zero value
indicates AFBC is fully supported, provided the architecture itself
supports AFBC, allowing backwards-compatibility with Midgard. Bits 0 and
15 indicate that AFBC support is absent for texturing and rendering
respectively.
The user experiencing the fault reports that AFBC_FEATURES reads back
0x10001 on their system, confirming the architectural lack of AFBC.
Userspace needs this parameter to know to disable AFBC on that
chip, and perhaps others.
v2: Fix typo from copy-paste fail.
v3: Bump the UABI version. This commit was cherry-picked from another
series so chalking this up to a rebase fail.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210604130011.3203-1-alyssa.rosenzweig@collabora.com
Diffstat (limited to 'drivers/gpu/drm/panfrost/panfrost_drv.c')
-rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_drv.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c index ca07098a6141..1596559f3d14 100644 --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -63,6 +63,7 @@ static int panfrost_ioctl_get_param(struct drm_device *ddev, void *data, struct PANFROST_FEATURE(THREAD_MAX_BARRIER_SZ, thread_max_barrier_sz); PANFROST_FEATURE(COHERENCY_FEATURES, coherency_features); + PANFROST_FEATURE(AFBC_FEATURES, afbc_features); PANFROST_FEATURE_ARRAY(TEXTURE_FEATURES, texture_features, 3); PANFROST_FEATURE_ARRAY(JS_FEATURES, js_features, 15); PANFROST_FEATURE(NR_CORE_GROUPS, nr_core_groups); @@ -547,6 +548,7 @@ DEFINE_DRM_GEM_FOPS(panfrost_drm_driver_fops); * Panfrost driver version: * - 1.0 - initial interface * - 1.1 - adds HEAP and NOEXEC flags for CREATE_BO + * - 1.2 - adds AFBC_FEATURES query */ static const struct drm_driver panfrost_drm_driver = { .driver_features = DRIVER_RENDER | DRIVER_GEM | DRIVER_SYNCOBJ, @@ -559,7 +561,7 @@ static const struct drm_driver panfrost_drm_driver = { .desc = "panfrost DRM", .date = "20180908", .major = 1, - .minor = 1, + .minor = 2, .gem_create_object = panfrost_gem_create_object, .prime_handle_to_fd = drm_gem_prime_handle_to_fd, |