Add the missing locks to the IRQ enable/disable paths, and fix a comment in the interrupt handler: reading the ISR clears down the status bits, but does not reset the interrupt so it can signal again. That seems to require a write.
Signed-off-by: Russell King rmk+kernel@armlinux.org.uk --- drivers/gpu/drm/armada/armada_crtc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/armada/armada_crtc.c b/drivers/gpu/drm/armada/armada_crtc.c index 03eeee11dd5b..42a40daff132 100644 --- a/drivers/gpu/drm/armada/armada_crtc.c +++ b/drivers/gpu/drm/armada/armada_crtc.c @@ -519,8 +519,9 @@ static irqreturn_t armada_drm_irq(int irq, void *arg) u32 v, stat = readl_relaxed(dcrtc->base + LCD_SPU_IRQ_ISR);
/* - * This is rediculous - rather than writing bits to clear, we - * have to set the actual status register value. This is racy. + * Reading the ISR appears to clear bits provided CLEAN_SPU_IRQ_ISR + * is set. Writing has some other effect to acknowledge the IRQ - + * without this, we only get a single IRQ. */ writel_relaxed(0, dcrtc->base + LCD_SPU_IRQ_ISR);
@@ -1116,16 +1117,22 @@ armada_drm_crtc_set_property(struct drm_crtc *crtc, static int armada_drm_crtc_enable_vblank(struct drm_crtc *crtc) { struct armada_crtc *dcrtc = drm_to_armada_crtc(crtc); + unsigned long flags;
+ spin_lock_irqsave(&dcrtc->irq_lock, flags); armada_drm_crtc_enable_irq(dcrtc, VSYNC_IRQ_ENA); + spin_unlock_irqrestore(&dcrtc->irq_lock, flags); return 0; }
static void armada_drm_crtc_disable_vblank(struct drm_crtc *crtc) { struct armada_crtc *dcrtc = drm_to_armada_crtc(crtc); + unsigned long flags;
+ spin_lock_irqsave(&dcrtc->irq_lock, flags); armada_drm_crtc_disable_irq(dcrtc, VSYNC_IRQ_ENA); + spin_unlock_irqrestore(&dcrtc->irq_lock, flags); }
static const struct drm_crtc_funcs armada_crtc_funcs = { @@ -1415,6 +1422,7 @@ static int armada_drm_crtc_create(struct drm_device *drm, struct device *dev, CFG_PDWN64x66, dcrtc->base + LCD_SPU_SRAM_PARA1); writel_relaxed(0x2032ff81, dcrtc->base + LCD_SPU_DMA_CTRL1); writel_relaxed(dcrtc->irq_ena, dcrtc->base + LCD_SPU_IRQ_ENA); + readl_relaxed(dcrtc->base + LCD_SPU_IRQ_ISR); writel_relaxed(0, dcrtc->base + LCD_SPU_IRQ_ISR);
ret = devm_request_irq(dev, irq, armada_drm_irq, 0, "armada_drm_crtc",