-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 22/04/15 11:40, Ben Dooks wrote: > On 27/03/15 17:46, Wolfram Sang wrote: >> On Tue, Mar 17, 2015 at 12:04:29PM +0000, Ben Dooks wrote: >>> The i2c-gpio driver can be used in systems where the GPIO >>> itself is provided by a GPIO driver that may be sleeping (for >>> example, SPI or USB). In this case, it is preferable to use >>> the _cansleep() variants of the GPIO code. >>> >>> We can only fix this up for the case where the i2c-gpio >>> implementation provides open-drain outputs as there are no >>> gpio_direction_xxx_cansleep() provided. >>> >>> This removes the issues on the customer system with the >>> console constantly showing the following warning: >>> >>> WARNING: CPU: 0 PID: 1 at drivers/gpio/gpiolib.c:2389 >>> gpiod_set_raw_value > >> ??? It will silence a warning but will totally break the timing >> in case sleeping is needed? I'd think the warning is very >> suitable. > > This basically causes our system to fail to boot in any suitable > time. > > The problem is that the i2c bus is on the end of an SPI bus which > means that the identification EEPROM tests and other items read > from it will run through a gpio chip that is marked as 'can > sleep'. > > I don't have the exact times, but I got bored after the first > thirty seconds of these log messages and immediately patched them > out of the kernel. Would a probe time warn and then doing the same change be ok? - -- Ben Dooks http://www.codethink.co.uk/ Senior Engineer Codethink - Providing Genius -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJVN180AAoJEMuhVOkVU3uzxSEH/jwcYKeGH8oz9k3aFfg6qHVf u57lz2q2v2ajAhL6vA5zFOqBvJmzJnoy45uvhbZeZNV9C+F104a+Yk2Z+QIqJh5t uQ5kZ5WCQ8QX/tS5cWEhq76zHvfooLa6Qw0WbuAKn36fA8n9Xedhuu4ozW9ofhZf +dpTJQ3eK5RhaNyhSxFtXrfts4TgAHFI4UluUA9lyZ6acAWRDB3WWNt2sbol9os2 xrD5F2818etjsqWslJEw3MgTLHZFfswKAhYRiRjbasGpoLL0YGvfLsC+cnJrrVVy N4OBsFs8KiXMk3MsuN1IxMa0fWvKhzbmMHmM74flp2tmStJ2iJbP6ta9U2Su3oU= =A7M6 -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
