Il 08/02/21 19:18, Stephen Boyd ha scritto:

Quoting AngeloGioacchino Del Regno (2021-01-14 14:10:53)

quoted

The GPU IOMMU depends on this clock and the hypervisor will crash
the SoC if this clock gets disabled because the secure contexts
that have been set on this IOMMU by the bootloader will become
unaccessible (or they get reset).
Mark this clock as critical to avoid this issue when the Adreno
GPU is enabled.

Signed-off-by: AngeloGioacchino Del Regno <redacted>
---
  drivers/clk/qcom/gcc-msm8998.c | 6 ++++++
  1 file changed, 6 insertions(+)

diff --git a/drivers/clk/qcom/gcc-msm8998.c b/drivers/clk/qcom/gcc-msm8998.c
index c8d4c0348952..afea60a3ef43 100644
--- a/drivers/clk/qcom/gcc-msm8998.c
+++ b/drivers/clk/qcom/gcc-msm8998.c

@@ -2081,6 +2081,12 @@ static struct clk_branch gcc_gpu_cfg_ahb_clk = {
                 .hw.init = &(struct clk_init_data){
                         .name = "gcc_gpu_cfg_ahb_clk",
                         .ops = &clk_branch2_ops,
+                       /*
+                        * The GPU IOMMU depends on this clock and hypervisor
+                        * will crash the SoC if this clock goes down, due to
+                        * secure contexts protection.
+                        */
+                       .flags = CLK_IS_CRITICAL,
                 },
         },

Please send a followup patch that hits the branch on at probe time and
removes this clk from the kernel. That will save some memory and
overhead of worrying about this clk.

Will do!