From 0df34a807310325cfb910276d631c949aa008d91 Mon Sep 17 00:00:00 2001 From: Liviu Dudau Date: Tue, 23 May 2017 14:18:18 +0100 Subject: [PATCH] drm/mali-dp: Check PM status when sharing interrupt lines If an instance of Mali DP hardware shares the interrupt line with another hardware (usually another instance of the Mali DP) its interrupt handler can get called when the device is suspended. Check the PM status before making access to the hardware registers to avoid deadlocks. Signed-off-by: Liviu Dudau --- drivers/gpu/drm/arm/malidp_hw.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c index 28360b8542f7..17bca99e8ac8 100644 --- a/drivers/gpu/drm/arm/malidp_hw.c +++ b/drivers/gpu/drm/arm/malidp_hw.c @@ -766,12 +766,17 @@ static irqreturn_t malidp_de_irq(int irq, void *arg) u32 status, mask, dc_status; irqreturn_t ret = IRQ_NONE; - if (!drm->dev_private) - return IRQ_HANDLED; - hwdev = malidp->dev; de = &hwdev->map.de_irq_map; + /* + * if we are suspended it is likely that we were invoked because + * we share an interrupt line with some other driver, don't try + * to read the hardware registers + */ + if (hwdev->pm_suspended) + return IRQ_NONE; + /* first handle the config valid IRQ */ dc_status = malidp_hw_read(hwdev, hwdev->map.dc_base + MALIDP_REG_STATUS); if (dc_status & hwdev->map.dc_irq_map.vsync_irq) { @@ -854,6 +859,14 @@ static irqreturn_t malidp_se_irq(int irq, void *arg) struct malidp_hw_device *hwdev = malidp->dev; u32 status, mask; + /* + * if we are suspended it is likely that we were invoked because + * we share an interrupt line with some other driver, don't try + * to read the hardware registers + */ + if (hwdev->pm_suspended) + return IRQ_NONE; + status = malidp_hw_read(hwdev, hwdev->map.se_base + MALIDP_REG_STATUS); if (!(status & hwdev->map.se_irq_map.irq_mask)) return IRQ_NONE; -- 2.20.1