[PATCH 11/13] drm/msm: Support KMS backends without a display IRQ

[Jayant Shekhar]

Some MSM KMS backends receive display events through firmware or
another transport and therefore have no host-visible display interrupt.
Rejecting such a backend during common KMS initialization prevents
it from using the MSM DRM framework.

Allow KMS backends to use IRQ_NOTCONNECTED. DCP receives VSYNC and
frame-scan completion as asynchronous HFI events over VirtIO; its IPCC
interrupt is reserved for power-notify acknowledgments. Existing
IRQ-backed KMS implementations retain their current request and
teardown flow.

Signed-off-by: Jayant Shekhar <jayant.shekhar@xxxxxxxxxxxxxxxx>
Assisted-by: LLM
---
 drivers/gpu/drm/msm/msm_kms.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_kms.c b/drivers/gpu/drm/msm/msm_kms.c
index e5d0ea629448..1870a7008ead 100644
--- a/drivers/gpu/drm/msm/msm_kms.c
+++ b/drivers/gpu/drm/msm/msm_kms.c
@@ -72,7 +72,7 @@ static int msm_irq_install(struct drm_device *dev, unsigned int irq)
 	int ret;
 
 	if (irq == IRQ_NOTCONNECTED)
-		return -ENOTCONN;
+		return 0;
 
 	msm_irq_preinstall(dev);
 

-- 
2.43.0