Messages in this thread | | | Subject | Re: [PATCH v1] gpio: dwapb: mask/unmask IRQ when disable/enable it | From | luojiaxing <> | Date | Tue, 1 Dec 2020 16:59:21 +0800 |
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On 2020/11/30 19:22, Andy Shevchenko wrote: > On Mon, Nov 30, 2020 at 05:36:19PM +0800, Luo Jiaxing wrote: >> The mask and unmask registers are not configured in dwapb_irq_enable() and >> dwapb_irq_disable(). In the following situations, the IRQ will be masked by >> default after the IRQ is enabled: >> >> mask IRQ -> disable IRQ -> enable IRQ >> >> In this case, the IRQ status of GPIO controller is inconsistent with it's >> irq_data too. For example, in __irq_enable(), IRQD_IRQ_DISABLED and >> IRQD_IRQ_MASKED are both clear, but GPIO controller do not perform unmask. > Sounds a bit like a papering over the issue which is slightly different. > Can you elaborate more, why ->irq_mask() / ->irq_unmask() are not being called?
Sure, The basic software invoking process is as follows:
Release IRQ: free_irq() -> __free_irq() -> irq_shutdown() ->__irq_disable()
Disable IRQ: disable_irq() -> __disable_irq_nosync() -> __disable_irq -> irq_disable -> __irq_disable()
As shown before, both will call __irq_disable(). The code of it is as follows:
if (irqd_irq_disabled(&desc->irq_data)) { if (mask) mask_irq(desc);
} else { irq_state_set_disabled(desc); if (desc->irq_data.chip->irq_disable) { desc->irq_data.chip->irq_disable(&desc->irq_data); irq_state_set_masked(desc); } else if (mask) { mask_irq(desc); } }
Because gpio-dwapb.c provides the hook function of irq_disable, __irq_disable() will directly calls chip->irq_disable() instead of mask_irq().
For irq_enable(), it's similar and the code is as follows:
if (!irqd_irq_disabled(&desc->irq_data)) { unmask_irq(desc); } else { irq_state_clr_disabled(desc); if (desc->irq_data.chip->irq_enable) { desc->irq_data.chip->irq_enable(&desc->irq_data); irq_state_clr_masked(desc); } else { unmask_irq(desc); } }
Similarly, because gpio-dwapb.c provides the hook function of irq_enable, irq_enable() will directly calls chip->irq_enable() but does not call unmask_irq().
Therefore, the current handle is as follows:
API of IRQ: | mask_irq() | disable_irq() | enable_irq()
gpio-dwapb.c: | chip->irq_mask() | chip->irq_diable() | chip->irq_enable()
I do not know why irq_enable() only calls chip->irq_enable(). However, the code shows that irq_enable() clears the disable and masked flags in the irq_data state.
Therefore, for gpio-dwapb.c, I thinks ->irq_enable also needs to clear the disable and masked flags in the hardware register.
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