Quoting Vinod Polimera (2022-04-25 23:02:11)
Avoid clearing irqs and derefernce hw_intr when hw_intr is null.
Presumably this is only the case when the display driver doesn't fully probe and something probe defers? Can you clarify how this situation happens?
BUG: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Call trace: dpu_core_irq_uninstall+0x50/0xb0 dpu_irq_uninstall+0x18/0x24 msm_drm_uninit+0xd8/0x16c msm_drm_bind+0x580/0x5fc try_to_bring_up_master+0x168/0x1c0 __component_add+0xb4/0x178 component_add+0x1c/0x28 dp_display_probe+0x38c/0x400 platform_probe+0xb0/0xd0 really_probe+0xcc/0x2c8 __driver_probe_device+0xbc/0xe8 driver_probe_device+0x48/0xf0 __device_attach_driver+0xa0/0xc8 bus_for_each_drv+0x8c/0xd8 __device_attach+0xc4/0x150 device_initial_probe+0x1c/0x28
Fixes: a73033619ea ("drm/msm/dpu: squash dpu_core_irq into dpu_hw_interrupts")
The fixes tag looks odd. In dpu_core_irq_uninstall() at that commit it is dealing with 'irq_obj' which isn't a pointer. After commit f25f656608e3 ("drm/msm/dpu: merge struct dpu_irq into struct dpu_hw_intr") dpu_core_irq_uninstall() starts using 'hw_intr' which is allocated on the heap. If we backported this patch to a place that had a73033619ea without f25f656608e3 it wouldn't make any sense.
Signed-off-by: Vinod Polimera quic_vpolimer@quicinc.com
drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c index c515b7c..ab28577 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c @@ -599,6 +599,9 @@ void dpu_core_irq_uninstall(struct dpu_kms *dpu_kms) { int i;
if (!dpu_kms->hw_intr)return;pm_runtime_get_sync(&dpu_kms->pdev->dev); for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++)