Hi Dan,
On 04/07/2016 03:41 AM, Dan Carpenter wrote:
> Hello Yakir Yang,
>
> The patch 7b4b7a8db439: "drm: bridge: analogix/dp: Fix the possible
> dead lock in bridge disable time" from Feb 15, 2016, leads to the
> following static checker warning:
>
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c:875
> analogix_dp_irq_thread()
> warn: bitwise AND condition is false here
>
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> 869 static irqreturn_t analogix_dp_irq_thread(int irq, void *arg)
> 870 {
> 871 struct analogix_dp_device *dp = arg;
> 872 enum dp_irq_type irq_type;
> 873
> 874 irq_type = analogix_dp_get_irq_type(dp);
> 875 if (irq_type & DP_IRQ_TYPE_HP_CABLE_IN ||
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> This is never true. Maybe test_bit() for these?
Ah, yep, it's an error here. The enum value of DP_IRQ_TYPE_HP_CABLE_IN
is zero, so even if analogix_dp_get_irq_type return the CABLE_IN event,
driver
could not send the drm hpd event rightly.
Good catch, would need to assign the new enum value, like
enum dp_irq_type {
- DP_IRQ_TYPE_HP_CABLE_IN,
- DP_IRQ_TYPE_HP_CABLE_OUT,
- DP_IRQ_TYPE_HP_CHANGE,
- DP_IRQ_TYPE_UNKNOWN,
+ DP_IRQ_TYPE_HP_CABLE_IN = BIT(0),
+ DP_IRQ_TYPE_HP_CABLE_OUT = BIT(1),
+ DP_IRQ_TYPE_HP_CHANGE = BIT(2),
+ DP_IRQ_TYPE_UNKNOWN = BIT(3),
};
Thanks for pointing out, would send patch to fix that soon.
- Yakir
>
> 876 irq_type & DP_IRQ_TYPE_HP_CABLE_OUT) {
> 877 dev_dbg(dp->dev, "Detected cable status changed!\n");
> 878 if (dp->drm_dev)
> 879 drm_helper_hpd_irq_event(dp->drm_dev);
> 880 }
> 881
> 882 if (irq_type != DP_IRQ_TYPE_UNKNOWN) {
> 883 analogix_dp_clear_hotplug_interrupts(dp);
> 884 analogix_dp_unmute_hpd_interrupt(dp);
> 885 }
> 886
> 887 return IRQ_HANDLED;
> 888 }
>
> regards,
> dan carpenter
>
>
>
