On 9/27/21 5:38 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> clang does not understand the "mrc%?" syntax:
>
> drivers/usb/gadget/udc/pxa25x_udc.c:2330:11: error: invalid % escape in inline assembly string
>
> I don't understand it either, but removing the %? here gets it to build.
> This is probably wrong and someone else should do a proper patch.
>
> Any suggestions?
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/usb/gadget/udc/pxa25x_udc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/udc/pxa25x_udc.c b/drivers/usb/gadget/udc/pxa25x_udc.c
> index a09ec1d826b2..52cdfd8212d6 100644
> --- a/drivers/usb/gadget/udc/pxa25x_udc.c
> +++ b/drivers/usb/gadget/udc/pxa25x_udc.c
> @@ -2325,7 +2325,7 @@ static int pxa25x_udc_probe(struct platform_device *pdev)
> pr_info("%s: version %s\n", driver_name, DRIVER_VERSION);
>
> /* insist on Intel/ARM/XScale */
> - asm("mrc%? p15, 0, %0, c0, c0" : "=r" (chiprev));
> + asm("mrc p15, 0, %0, c0, c0" : "=r" (chiprev));
You could consider using read_cpuid() from
arch/arm/include/asm/cputype.h as this driver really does not seem to
have portability in mind.
> if ((chiprev & CP15R0_VENDOR_MASK) != CP15R0_XSCALE_VALUE) {
> pr_err("%s: not XScale!\n", driver_name);
> return -ENODEV;
>
--
Florian
