On 10/08/2023 17:44, Greg Kroah-Hartman wrote: > On Thu, Aug 10, 2023 at 10:50:42AM +0200, Krzysztof Kozlowski wrote: >> `devtype` is enum, thus cast of pointer on 64-bit compile test with W=1 >> causes: >> >> mxs-auart.c:1598:15: error: cast to smaller integer type 'enum mxs_auart_type' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast] >> >> Cc: Andi Shyti <andi.shyti@xxxxxxxxxx> >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >> --- >> drivers/tty/serial/mxs-auart.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c >> index 8eeecf8ad359..a9b32722b049 100644 >> --- a/drivers/tty/serial/mxs-auart.c >> +++ b/drivers/tty/serial/mxs-auart.c >> @@ -1595,7 +1595,7 @@ static int mxs_auart_probe(struct platform_device *pdev) >> return -EINVAL; >> } >> >> - s->devtype = (enum mxs_auart_type)of_device_get_match_data(&pdev->dev); >> + s->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev); > > This feels like a compiler issue as devtype is a enum mxs_auart_type > variable, so the cast shoudl be correct. While the cast is obviously safe here, the warning in general is reasonable - people were make too many mistakes by assuming pointers are integers... Just for the record (not saying that others doing is proof of correctness): https://lore.kernel.org/lkml/20230809-cbl-1903-v1-1-df9d66a3ba3e@xxxxxxxxxx/T/ But maybe Nathan can share his thoughts whether we should just disable this warning for kernel? > > And if not, unitptr_t isn't a valid kernel type, so that's not a good It is in include/linux/types.h, so do you mean that it is not recommended for in-kernel usage? I can go with kernel_ulong_t - which is a kernel type - if the cast is agreed. > solution either. Worst case, it's how big a pointer is, which is not > going to be what an enum is if you have a sane compiler :( Best regards, Krzysztof
