[PATCH AUTOSEL 5.4 05/10] drm/amd/display: Prevent bandwidth overflow

[PATCH AUTOSEL 5.4 05/10] drm/amd/display: Prevent bandwidth overflow

[Sasha Levin]

From: Chris Park <Chris.Park@amd.com>

[ Upstream commit 80089dd8410f356d5104496d5ab71a66a4f4646b ]

[Why]
At very high pixel clock, bandwidth calculation exceeds 32 bit size
and overflow value. This causes the resulting selection of link rate
to be inaccurate.

[How]
Change order of operation and use fixed point to deal with integer
accuracy. Also address bug found when forcing link rate.

Signed-off-by: Chris Park <Chris.Park@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 47cefc05fd3f5..f933791f1fbbb 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -2906,11 +2906,14 @@ uint32_t dc_bandwidth_in_kbps_from_timing(
 {
 	uint32_t bits_per_channel = 0;
 	uint32_t kbps;
+	struct fixed31_32 link_bw_kbps;
 
 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
 	if (timing->flags.DSC) {
-		kbps = (timing->pix_clk_100hz * timing->dsc_cfg.bits_per_pixel);
-		kbps = kbps / 160 + ((kbps % 160) ? 1 : 0);
+		link_bw_kbps = dc_fixpt_from_int(timing->pix_clk_100hz);
+		link_bw_kbps = dc_fixpt_div_int(link_bw_kbps, 160);
+		link_bw_kbps = dc_fixpt_mul_int(link_bw_kbps, timing->dsc_cfg.bits_per_pixel);
+		kbps = dc_fixpt_ceil(link_bw_kbps);
 		return kbps;
 	}
 #endif
-- 
2.27.0

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

[PATCH AUTOSEL 5.4 06/10] drm/amdkfd: Fix leak in dmabuf import

[Sasha Levin]

From: Felix Kuehling <Felix.Kuehling@amd.com>

[ Upstream commit c897934da15f182ce99536007f8ef61c4748c07e ]

Release dmabuf reference before returning from kfd_ioctl_import_dmabuf.
amdgpu_amdkfd_gpuvm_import_dmabuf takes a reference to the underlying
GEM BO and doesn't keep the reference to the dmabuf wrapper.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 1d3cd5c50d5f2..4a0ef9268918c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1664,6 +1664,7 @@ static int kfd_ioctl_import_dmabuf(struct file *filep,
 	}
 
 	mutex_unlock(&p->mutex);
+	dma_buf_put(dmabuf);
 
 	args->handle = MAKE_HANDLE(args->gpu_id, idr_handle);
 
@@ -1673,6 +1674,7 @@ static int kfd_ioctl_import_dmabuf(struct file *filep,
 	amdgpu_amdkfd_gpuvm_free_memory_of_gpu(dev->kgd, (struct kgd_mem *)mem);
 err_unlock:
 	mutex_unlock(&p->mutex);
+	dma_buf_put(dmabuf);
 	return r;
 }
 
-- 
2.27.0

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx