From: Florian Fainelli <f.fainelli@gmail.com>
To: Arnd Bergmann <arnd@kernel.org>, Daniel Mack <daniel@zonque.org>,
Haojian Zhuang <haojian.zhuang@gmail.com>,
Robert Jarzmik <robert.jarzmik@free.fr>,
Felipe Balbi <balbi@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
Rikard Falkeborn <rikard.falkeborn@gmail.com>,
linux-arm-kernel@lists.infradead.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH] [RFC] usb: gadget: avoid unusual inline assembly
Date: Wed, 13 Oct 2021 11:54:45 -0700 [thread overview]
Message-ID: <877c70bd-52ef-95ed-1029-e84911e9162b@gmail.com> (raw)
In-Reply-To: <20210927123830.1278953-1-arnd@kernel.org>
On 9/27/21 5:38 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> 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@arndb.de>
> ---
> 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
prev parent reply other threads:[~2021-10-13 18:54 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-27 12:38 [PATCH] [RFC] usb: gadget: avoid unusual inline assembly Arnd Bergmann
2021-10-13 12:03 ` Greg Kroah-Hartman
2021-10-13 18:35 ` Nick Desaulniers
2021-10-13 18:54 ` Florian Fainelli [this message]
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