[PATCH v3 03/12] drm/tyr: Set interconnect coherency during probe

[Deborah Brouwer <deborah.brouwer@collabora.com>]

Currently GpuInfo reports the interconnect coherency protocol as none
without actually reading the `COHERENCY_ENABLE` register.

Although the result is the same, write `NO_COHERENCY` to the register
during probe and then read back the register to populate the GpuInfo
struct.

This ensures that GpuInfo is populated consistently and is always as
accurate as possible by reporting the register values directly.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
---
 drivers/gpu/drm/tyr/driver.rs | 5 +++++
 drivers/gpu/drm/tyr/gpu.rs    | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
index 3ebb5e08bfca342f136e8d365b1d9dcb6cc3dbca..7232d9f9547c239689dc424380109a4e5140dd84 100644
--- a/drivers/gpu/drm/tyr/driver.rs
+++ b/drivers/gpu/drm/tyr/driver.rs
@@ -136,6 +136,11 @@ fn probe(
         issue_soft_reset(pdev.as_ref(), &iomem)?;
         gpu::l2_power_on(pdev.as_ref(), &iomem)?;
 
+        let io = (*iomem).access(pdev.as_ref())?;
+        // FIXME: This needs to be set properly once we get
+        // device_get_dma_attr() properly exposed to the rust drivers.
+        io.write_reg(COHERENCY_ENABLE::zeroed().with_l2_cache_protocol_select(CoherencyMode::None));
+
         let gpu_info = GpuInfo::new(pdev.as_ref(), &iomem)?;
         gpu_info_log(pdev.as_ref(), &iomem)?;
 
diff --git a/drivers/gpu/drm/tyr/gpu.rs b/drivers/gpu/drm/tyr/gpu.rs
index 4a50055b415c693a89cb99dba241b21351a14149..d5240f4567ca4e763b09e015908bdc5c22276e0d 100644
--- a/drivers/gpu/drm/tyr/gpu.rs
+++ b/drivers/gpu/drm/tyr/gpu.rs
@@ -60,7 +60,7 @@ pub(crate) fn new(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result<Self> {
                 io.read(TEXTURE_FEATURES::at(3)).supported_formats().get(),
             ],
             as_present: io.read(AS_PRESENT).into_raw(),
-            selected_coherency: uapi::drm_panthor_gpu_coherency_DRM_PANTHOR_GPU_COHERENCY_NONE,
+            selected_coherency: io.read(COHERENCY_ENABLE).into_raw(),
             shader_present: io.read(SHADER_PRESENT).into_raw(),
             l2_present: io.read(L2_PRESENT).into_raw(),
             tiler_present: io.read(TILER_PRESENT).into_raw(),

-- 
2.52.0