Re: [PATCH RFC] gpio: brcmstb: Properly account for empty banks

[Justin Chen <justinpopo6@xxxxxxxxx>]

On Mon, Aug 6, 2018 at 6:18 PM, Gregory Fong <gregory.0xf0@xxxxxxxxx> wrote:
> Hi Justin,
>
> I got this same patch 3 times in a row in one day, not sure why. :-)
Good to hear from you Gregory. :) Sorry mail server issue hehe
>
> On Wed, Jul 18, 2018 at 2:12 PM,  <justinpopo6@xxxxxxxxx> wrote:
>> From: Justin Chen <justinpopo6@xxxxxxxxx>
>>
>> On some chips we have empty banks or a hole in the register space.
>> The driver assumes all banks are consecutive and the same size.
>
> It does assume both of these, but if this workaround works, then only
> the former is a problem, right?  Consider omitting the mention of it
> being the same size if it's not relevant for the change.
Oh ok, I see what you are getting at here. I think I might just rephrase the
commit message as a whole. Now that I am reading it again, it is a bit
confusing.
>
>> To work around this, we create a fake bank where there is a hole
>> and keep it out of the linked list so it won't be called or initialized
>
> The idea seems OK, and it looks like this should already even be
> handled properly by brcmstb_gpio_irq_map().  I think the main issue is
> informational; the info line printed at the end of probe would give
> the appearance of the driver registering more GPIOs than it actually
> does.  Please update that to be clearer about what is actually
> registered.
Without the patch we actually fail at brcmstb_gpio_sanity_check_banks because of
        if (res_num_banks != num_banks) {
                dev_err(dev, "Mismatch in banks: res had %d,
bank-widths had %d\n",
                                res_num_banks, num_banks);
                return -EINVAL;
        } ...
Ok I'll see what I can do. The information is already misleading
because not all banks use all 32 gpios.

Thanks,
Justin
>
> Best regards,
> Gregory
--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html