(re-added some context, CC Linus, Alexandre, linux-gpio) On Tue, Oct 7, 2014 at 2:38 PM, Mark Brown <broonie@xxxxxxxxxx> wrote: > On Tue, Oct 07, 2014 at 02:32:57PM +0200, Geert Uytterhoeven wrote: >> Unfortunately there's no equivalent code for platform data, and the >> uninitialized default of 0 for gpio_hp_det and gpio_mic_det doesn't >> play well with asm-generic's gpio_is_valid(): >> >> static inline bool gpio_is_valid(int number) >> { >> return number >= 0 && number < ARCH_NR_GPIOS; >> } >> >> Hence on r8a7740/armadillo-legacy, which uses platform devices instead of DT: > >> sh-mobile-hdmi sh-mobile-hdmi: SH Mobile HDMI Audio Codec >> sh-mobile-hdmi sh-mobile-hdmi: ASoC: DAPM unknown pin Headphones >> sh-mobile-hdmi sh-mobile-hdmi: ASoC: DAPM unknown pin Mic Jack > >> After that the kernel log is spammed ca. 7 times per second with: > >> sh-mobile-hdmi sh-mobile-hdmi: ASoC: DAPM unknown pin Headphones > >> Reverting commit 3fe240326cc395c66 ("ASoC: simple-card: Add mic and >> hp detect gpios.") fixes this. > > The fix here is to not allow 0 as a GPIO in the core code (which > should've been there already). Unfortunately it's not there. And it's not as simple as changing the definition of gpio_is_valid() (crash in gpio_get_value()): gpiochip_add: GPIOs 0..211 (r8a7740_pfc) failed to register sh-pfc pfc-r8a7740: failed to init GPIO chip, ignoring... sh-pfc pfc-r8a7740: r8a7740_pfc support registered Unable to handle kernel NULL pointer dereference at virtual address 0000004c Quoting Linus (https://lkml.org/lkml/2014/9/4/464): "Fixing the old global GPIO numberspace API is a waste of time IMO". Hence I've just sent a patch to initialize the GPIO numbers with -ENOENT. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html