| From | Linus Walleij <> | Date | Wed, 31 Jan 2024 20:38:28 +0100 | Subject | Re: [PATCH 05/22] gpio: don't set label from irq helpers |
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On Tue, Jan 30, 2024 at 1:48 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > We will soon serialize access to the descriptor label using SRCU. The > write-side of the protection will require calling synchronize_srcu() > which must not be called from atomic context. We have two irq helpers: > gpiochip_lock_as_irq() and gpiochip_unlock_as_irq() that set the label > if the GPIO is not requested but is being used as interrupt. They are > called with a spinlock held from the interrupt subsystem. > > They must not do it if we are to use SRCU so instead let's move the > special corner case to a dedicated getter. > > Let's use the flags of the descriptor to figure out whether we should > use the special "interrupt" label. > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
I would refine the commit message: what you do IIUC is that you simply avoid modifying a string, the label isn't set anymore, instead a const string is returned and it is selected from the state of an atomic variable (ha! smart!) and that is how the atomicity is achieved.
Anyway: Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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