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.
