Messages in this thread | | | From | Yash Shah <> | Subject | RE: [PATCH 3/4] gpio: sifive: Add GPIO driver for SiFive SoCs | Date | Mon, 25 Nov 2019 04:54:40 +0000 |
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> -----Original Message----- > From: Linus Walleij <linus.walleij@linaro.org> > Sent: 22 November 2019 17:58 > To: Bartosz Golaszewski <bgolaszewski@baylibre.com> > Cc: Yash Shah <yash.shah@sifive.com>; robh+dt@kernel.org; > mark.rutland@arm.com; palmer@dabbelt.com; Paul Walmsley ( Sifive) > <paul.walmsley@sifive.com>; aou@eecs.berkeley.edu; tglx@linutronix.de; > jason@lakedaemon.net; maz@kernel.org; bmeng.cn@gmail.com; > atish.patra@wdc.com; Sagar Kadam <sagar.kadam@sifive.com>; linux- > gpio@vger.kernel.org; devicetree@vger.kernel.org; linux- > riscv@lists.infradead.org; linux-kernel@vger.kernel.org; Sachin Ghadi > <sachin.ghadi@sifive.com> > Subject: Re: [PATCH 3/4] gpio: sifive: Add GPIO driver for SiFive SoCs > > On Tue, Nov 19, 2019 at 5:42 PM Bartosz Golaszewski > <bgolaszewski@baylibre.com> wrote: > > wt., 19 lis 2019 o 16:03 Linus Walleij <linus.walleij@linaro.org> napisał(a): > > > On Mon, Nov 18, 2019 at 11:15 AM Bartosz Golaszewski > > > <bgolaszewski@baylibre.com> wrote: > > > > > pon., 18 lis 2019 o 11:03 Yash Shah <yash.shah@sifive.com> napisał(a): > > > Is it really so? The bgpio_lock does protect the registers used by > > > regmap-mmio but unless the interrupt code is also using the same > > > registers it is fine to have a different lock for those. > > > > > > Is the interrupt code really poking into the very same registers as > > > passed to bgpio_init()? > > > > > > Of course it could be seen as a bit dirty to poke around in the same > > > memory space with regmap and the bgpio_* accessors but in practice > > > it's no problem if they never touch the same things. > > > > > > Yours, > > > Linus Walleij > > > > I'm wondering if it won't cause any inconsistencies when for example > > interrupts are being triggered on input lines while we're also reading > > their values? Seems to me it's just more clear to use a single lock > > for a register range. Most drivers using gpio-mmio do just that in > > their irq-related routines. > > OK good point. Just one lock for the whole thing is likely more maintainable > even if it works with two different locks. > > > Anyway: even without using bgpio_lock this code is inconsistent: if > > we're using regmap for interrupt registers, we should either decide to > > rely on locking provided by regmap or disable it and use a locally > > defined lock. > > OK makes sense, let's say we use the bgpio_lock everywhere for this. > > Yash: are you OK with this? (Haven't read the new patch set yet, maybe it is > already fixed...)
Yes, I am ok with this. I will be sending v3 soon with this change.
- Yash
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