On 15/06/2022 20:55, Abhinav Kumar wrote:
On 5/4/2022 5:16 PM, Dmitry Baryshkov wrote:
Follow the lead of MDP5 driver and check both DPU and MDSS devices for
the IOMMU specifiers.
Historically DPU devices had IOMMU specified in the MDSS device tree
node, but as some of MDP5 devices are being converted to the supported
by the DPU driver, the driver should adapt and check both devices.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index 143d6643be53..5ccda0766f6c 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -1004,14 +1004,22 @@ static int _dpu_kms_mmu_init(struct dpu_kms
*dpu_kms)
struct msm_mmu *mmu;
struct device *dpu_dev = dpu_kms->dev->dev;
struct device *mdss_dev = dpu_dev->parent;
+ struct device *iommu_dev;
domain = iommu_domain_alloc(&platform_bus_type);
if (!domain)
return 0;
- /* IOMMUs are a part of MDSS device tree binding, not the
- * MDP/DPU device. */
- mmu = msm_iommu_new(mdss_dev, domain);
+ /*
+ * IOMMUs can be a part of MDSS device tree binding, or the
+ * MDP/DPU device.
+ */
Can you please explain this a little more?
So even if some of the mdp5 devices are getting converted to use DPU
driver, their device trees are also updated right?
No. The DT describes the device, not the Linux drivers. So while
updating the drivers we should not change the DT.
In other words, if DPU driver was using mdss_dev to initialize the
iommu, why should the new devices which are going to use DPU have the
binding in the dpu_dev?
+ if (dev_iommu_fwspec_get(dpu_dev))
+ iommu_dev = dpu_dev;
+ else
+ iommu_dev = mdss_dev;
+
+ mmu = msm_iommu_new(iommu_dev, domain);
if (IS_ERR(mmu)) {
iommu_domain_free(domain);
return PTR_ERR(mmu);
--
With best wishes
Dmitry
