On Mon, Jun 20, 2022 at 10:08 PM Aidan MacDonald
<aidanmacdonald.0x0@xxxxxxxxx> wrote:
>
> To me "unmask" suggests that we write 1s to the register when
> an interrupt is enabled. This also makes sense because it's the
> opposite of what the "mask" register does (write 1s to disable
> an interrupt).
>
> But regmap-irq does the opposite: for a disabled interrupt, it
> writes 1s to "unmask" and 0s to "mask". This is surprising and
> deviates from the usual way mask registers are handled.
>
> Additionally, mask_invert didn't interact with unmask registers
> properly -- it caused them to be ignored entirely.
>
> Fix this by making mask and unmask registers orthogonal, using
> the following behavior:
>
> * Mask registers are written with 1s for disabled interrupts.
> * Unmask registers are written with 1s for enabled interrupts.
>
> This behavior supports both normal or inverted mask registers
> and separate set/clear registers via different combinations of
> mask_base/unmask_base. The mask_invert flag is made redundant,
> since an inverted mask register can be described more directly
> as an unmask register.
>
> To cope with existing drivers that rely on the old "backward"
> behavior, check for the broken_mask_unmask flag and swap the
> roles of mask/unmask registers. This is a compatibility measure
> which can be dropped once the drivers are updated to use the
> new, more consistent behavior.
...
> + if (ret != 0)
if (ret)
> + dev_err(d->map->dev, "Failed to sync masks in %x\n",
> + reg);
...
> + if (ret != 0)
Ditto.
> + dev_err(d->map->dev, "Failed to sync masks in %x\n",
...
> + /*
> + * Swap role of mask_base and unmask_base if mask bits are inverted.
the roles
> + *
> + * Historically, chips that specify both mask_base and unmask_base
> + * got inverted mask behavior; this was arguably a bug in regmap-irq
> + * and there was no way to get the normal, non-inverted behavior.
> + * Those chips will set the broken_mask_unmask flag. They don't set
> + * mask_invert so there is no need to worry about interactions with
> + * that flag.
> + */
Reading this comment perhaps the code needs a validator part that will
issue a WARN_ON / dev_warn() / etc in case where the above is not
satisfied?
...
> + if (ret != 0) {
if (ret)
> + dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
> + reg, ret);
...
> + if (ret != 0) {
Ditto.
> + dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
> + reg, ret);
--
With Best Regards,
Andy Shevchenko
