On Thu, Aug 08, 2019 at 03:25:43PM +0200, Stefan Roese wrote: > This patch fixes a backward compatibility issue, when boards use the > old style GPIO suffix "-gpio" instead of the new "-gpios". This > potential problem has been introduced by commit d99482673f95 ("serial: > mctrl_gpio: Check if GPIO property exisits before requesting it"). > > This patch now fixes this issue by iterating over all supported GPIO > suffixes by using the newly introduced for_each_gpio_suffix() helper. > > Also, the string buffer is now allocated on the stack to avoid the > problem of allocation in a loop and its potential failure. > for (i = 0; i < UART_GPIO_MAX; i++) { > enum gpiod_flags flags; > - char *gpio_str; > + const char *suffix; > + char gpio_str[32]; /* 32 is max size of property name */ Hmm... don't we have some define for the maximum length of property? Or maybe we can still continue using kasprintf() approach? > bool present; > + int k; > + > + /* > + * Check if GPIO property exists and continue if not. Iterate > + * over all supported GPIO suffixes (foo-gpios vs. foo-gpio). > + */ > + for_each_gpio_suffix(k, suffix) { > + snprintf(gpio_str, sizeof(gpio_str), "%s-%s", > + mctrl_gpios_desc[i].name, suffix); > + > + present = device_property_present(dev, gpio_str); > + if (present) > + break; > + } > > - /* Check if GPIO property exists and continue if not */ > - gpio_str = kasprintf(GFP_KERNEL, "%s-gpios", > - mctrl_gpios_desc[i].name); > - if (!gpio_str) > - continue; > - > - present = device_property_present(dev, gpio_str); Because there is no more explicit assignment of present outside of the loop, the compiler may warn about uninitialized variable in use... > - kfree(gpio_str); > if (!present) ...here. > continue; -- With Best Regards, Andy Shevchenko