Messages in this thread | | | Subject | Re: [PATCH] tty/serial: digicolor: Fix bad usage of IS_ERR_VALUE | From | Guenter Roeck <> | Date | Tue, 9 Feb 2016 18:37:46 -0800 |
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On 02/09/2016 07:26 AM, Arnd Bergmann wrote: > On Tuesday 09 February 2016 07:08:59 Guenter Roeck wrote: >> IS_ERR_VALUE() assumes that its parameter is an unsigned long. >> It can not be used to check if an unsigned int reflects an error. >> Doing so can result in the following build warning. >> >> drivers/tty/serial/digicolor-usart.c: In function ‘digicolor_uart_probe’: >> include/linux/err.h:21:38: warning: >> comparison is always false due to limited range of data type >> drivers/tty/serial/digicolor-usart.c:485:6: note: >> in expansion of macro ‘IS_ERR_VALUE’ >> >> If that warning is seen, an error return from platform_get_irq() is missed. >> >> > > The patch looks correct to me, but what compiler version and which kernel > tree is it that triggered the warning? > > Andrzej Hajda just modified the definition of IS_ERR_VALUE(), and the > changes are still under discussion, but I don't see that warning with > any of the versions. > I see it with gcc 5.1 and 5.2 (and W=1). I did not see / notice Andrzej's patch.
I agree that fixing the problem in IS_ERR_VALUE() is preferrable.
Guenter
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