On Mon, Mar 06, 2023 at 04:20:03PM +0200, Andy Shevchenko wrote: > On Mon, Mar 06, 2023 at 07:59:53AM -0500, William Breathitt Gray wrote: > > ... > > > - raw_spinlock_t lock; > > + spinlock_t lock; > > This is a regression. > That said, do we need a support of raw spin locks in the regmap IRQ? So this code has a similar need as the gpio-pcie-idio-24 patch: guard registers between handle_mask_sync() and set_type_config(); however, now we also need to protect registers in regmap_irq_thread(). We can't use a mutex here because regmap_irq_thread() is executed in an interrupt context so we cannot sleep. This might be a mistake in my understanding: I chose spinlock_t here because I believed it to map out to a raw_spinlock_t anyway underneath, whereas on RT kernels it would map out to whatever the equivalent is. I suspect this is not actually the case. Would using raw_spinlock_t explicitly be the correct way to go for this particular case? > > + u8 irq_mask[WS16C48_NUM_IRQS / WS16C48_NGPIO_PER_REG]; > > Can this be a bitmap? Or is it too over engineered with it? I also considered a bitmap at first, but I believe it adds an unnecessary abstraction in this particular case: irq_mask is just a buffer to hold the previous mask_buf state to check if it's changed when ws16c48_handle_mask_sync() is called. Since all we do with it is save the mask_buf directly, using the bitmap API seems like overkill. William Breathitt Gray
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