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authorArchit Taneja <architt@codeaurora.org>2016-06-15 16:20:45 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-13 14:09:45 -0700
commitc634cecad4c17e9761df9aa1cb22c707a402f4e8 (patch)
treed2348d60564a7097e798dd52501d2131b0f6c341
parentaea7e5ce4a52130b12ea23f15af7ac7aa1ab8ef9 (diff)
downloadlinux-linaro-stable-c634cecad4c17e9761df9aa1cb22c707a402f4e8.tar.gz
drm/bridge: adv7511: Fix mutex deadlock when interrupts are disabled
commit f0bfcc22d9822947b0ad3095e8363eab5261864c upstream. When the adv7511 i2c client doesn't have an interrupt line, we observe a deadlock on caused by trying to lock drm device's mode_config.mutex twice in the same context. Here is the sequence that causes it: ioctl DRM_IOCTL_MODE_GETCONNECTOR from userspace drm_mode_getconnector (acquires mode_config mutex) connector->fill_modes() drm_helper_probe_single_connector_modes connector_funcs->get_modes adv7511_encoder_get_modes adv7511_get_edid_block adv7511_irq_process drm_helper_hpd_irq_event (acquires mode_config mutex again) In adv7511_irq_process, don't call drm_helper_hpd_irq_event when not called from the interrupt handler. It doesn't serve any purpose there anyway. Signed-off-by: Archit Taneja <architt@codeaurora.org> Signed-off-by: Thong Ho <thong.ho.px@rvc.renesas.com> Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/gpu/drm/i2c/adv7511.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i2c/adv7511.c b/drivers/gpu/drm/i2c/adv7511.c
index cc91678..5b78963 100644
--- a/drivers/gpu/drm/i2c/adv7511.c
+++ b/drivers/gpu/drm/i2c/adv7511.c
@@ -429,7 +429,7 @@ static bool adv7511_hpd(struct adv7511 *adv7511)
return false;
}
-static int adv7511_irq_process(struct adv7511 *adv7511)
+static int adv7511_irq_process(struct adv7511 *adv7511, bool process_hpd)
{
unsigned int irq0, irq1;
int ret;
@@ -445,7 +445,7 @@ static int adv7511_irq_process(struct adv7511 *adv7511)
regmap_write(adv7511->regmap, ADV7511_REG_INT(0), irq0);
regmap_write(adv7511->regmap, ADV7511_REG_INT(1), irq1);
- if (irq0 & ADV7511_INT0_HDP && adv7511->encoder)
+ if (process_hpd && irq0 & ADV7511_INT0_HDP && adv7511->encoder)
drm_helper_hpd_irq_event(adv7511->encoder->dev);
if (irq0 & ADV7511_INT0_EDID_READY || irq1 & ADV7511_INT1_DDC_ERROR) {
@@ -463,7 +463,7 @@ static irqreturn_t adv7511_irq_handler(int irq, void *devid)
struct adv7511 *adv7511 = devid;
int ret;
- ret = adv7511_irq_process(adv7511);
+ ret = adv7511_irq_process(adv7511, true);
return ret < 0 ? IRQ_NONE : IRQ_HANDLED;
}
@@ -480,7 +480,7 @@ static int adv7511_wait_for_edid(struct adv7511 *adv7511, int timeout)
adv7511->edid_read, msecs_to_jiffies(timeout));
} else {
for (; timeout > 0; timeout -= 25) {
- ret = adv7511_irq_process(adv7511);
+ ret = adv7511_irq_process(adv7511, false);
if (ret < 0)
break;