drm/lima: fix shared irq handling on driver remove

[ Upstream commit a6683c690bbfd1f371510cb051e8fa49507f3f5e ]

lima uses a shared interrupt, so the interrupt handlers must be prepared
to be called at any time. At driver removal time, the clocks are
disabled early and the interrupts stay registered until the very end of
the remove process due to the devm usage.
This is potentially a bug as the interrupts access device registers
which assumes clocks are enabled. A crash can be triggered by removing
the driver in a kernel with CONFIG_DEBUG_SHIRQ enabled.
This patch frees the interrupts at each lima device finishing callback
so that the handlers are already unregistered by the time we fully
disable clocks.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240401224329.1228468-2-nunes.erico@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/lima/lima_gp.c b/drivers/gpu/drm/lima/lima_gp.c
index 6cf46b653e810f22fcacd509debacf115bb0ada8..ca3842f719842ef989949209a33513e464379a5e 100644 (file)
--- a/drivers/gpu/drm/lima/lima_gp.c
+++ b/drivers/gpu/drm/lima/lima_gp.c
@@ -324,7 +324,9 @@ int lima_gp_init(struct lima_ip *ip)
 
 void lima_gp_fini(struct lima_ip *ip)
 {
+       struct lima_device *dev = ip->dev;
 
+       devm_free_irq(dev->dev, ip->irq, ip);
 }
 
 int lima_gp_pipe_init(struct lima_device *dev)

diff --git a/drivers/gpu/drm/lima/lima_mmu.c b/drivers/gpu/drm/lima/lima_mmu.c
index a1ae6c252dc2b546bad5f12226cad197ff006808..8ca7047adbaca93d049174487b3332e221b0500e 100644 (file)
--- a/drivers/gpu/drm/lima/lima_mmu.c
+++ b/drivers/gpu/drm/lima/lima_mmu.c
@@ -118,7 +118,12 @@ int lima_mmu_init(struct lima_ip *ip)
 
 void lima_mmu_fini(struct lima_ip *ip)
 {
+       struct lima_device *dev = ip->dev;
+
+       if (ip->id == lima_ip_ppmmu_bcast)
+               return;
 
+       devm_free_irq(dev->dev, ip->irq, ip);
 }
 
 void lima_mmu_flush_tlb(struct lima_ip *ip)

diff --git a/drivers/gpu/drm/lima/lima_pp.c b/drivers/gpu/drm/lima/lima_pp.c
index 54b208a4a768e465d6daa6d8d0aa9ffd440894cb..d34c9e8840f45457451cae9bc54012bf6259c530 100644 (file)
--- a/drivers/gpu/drm/lima/lima_pp.c
+++ b/drivers/gpu/drm/lima/lima_pp.c
@@ -266,7 +266,9 @@ int lima_pp_init(struct lima_ip *ip)
 
 void lima_pp_fini(struct lima_ip *ip)
 {
+       struct lima_device *dev = ip->dev;
 
+       devm_free_irq(dev->dev, ip->irq, ip);
 }
 
 int lima_pp_bcast_resume(struct lima_ip *ip)
@@ -299,7 +301,9 @@ int lima_pp_bcast_init(struct lima_ip *ip)
 
 void lima_pp_bcast_fini(struct lima_ip *ip)
 {
+       struct lima_device *dev = ip->dev;
 
+       devm_free_irq(dev->dev, ip->irq, ip);
 }
 
 static int lima_pp_task_validate(struct lima_sched_pipe *pipe,