From: "andriy.shevchenko" <andriy.shevchenko@linux.intel.com>
To: "changlianzhi@uniontech.com" <changlianzhi@uniontech.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
"dmitry.torokhov" <dmitry.torokhov@gmail.com>,
gregkh <gregkh@linuxfoundation.org>,
jirislaby <jirislaby@kernel.org>, 282827961 <282827961@qq.com>
Subject: Re: [PATCH v6] tty: Fix the keyboard led light display problem
Date: Mon, 25 Oct 2021 15:03:05 +0300 [thread overview]
Message-ID: <YXac+bpVemXEp9XR@smile.fi.intel.com> (raw)
In-Reply-To: <202110250129181502896@uniontech.com>
On Mon, Oct 25, 2021 at 01:29:18AM +0800, changlianzhi@uniontech.com wrote:
> >>On Thu, Oct 21, 2021 at 10:05:11AM +0800, lianzhi chang wrote:
> >> Switching from the desktop environment to the tty environment,
> >> the state of the keyboard led lights and the state of the keyboard
> >> lock are inconsistent. This is because the attribute kb->kbdmode
> >> of the tty bound in the desktop environment (xorg) is set to
> >> VC_OFF, which causes the ledstate and kb->ledflagstate
> >> values of the bound tty to always be 0, which causes the switch
> >> from the desktop When to the tty environment, the LED light
> >> status is inconsistent with the keyboard lock status.
>
> >...
>
> >> + unsigned long leds;
> >> +
> >> + leds = (unsigned long)ledstate;
>
> >Can be one line.
>
> >But most important question you are ignoring to answer / address is why do you
> >use casting?
> >>But most important question you are ignoring to answer / address is why do you
> >>use casting?
> Casting is used here because:
> The second parameter of test_bit is "volatile unsigned long *addr" (see constant_test_bit() in /arch/x86/include/asm/bitops.h), but ledstate is an "unsigned int" type. If casting is not used,
> compile Will report an error.
Wait, you are casting pointer to an integer?!
This is completely wrong in this case!
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2021-10-25 12:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20211021020511.18016-1-changlianzhi@uniontech.com>
2021-10-22 15:13 ` [PATCH v6] tty: Fix the keyboard led light display problem Andy Shevchenko
[not found] ` <202110250129181502896@uniontech.com>
2021-10-25 12:03 ` andriy.shevchenko [this message]
[not found] ` <202110251224440412487@uniontech.com>
2021-10-25 12:57 ` andriy.shevchenko
2021-10-25 5:12 ` Dmitry Torokhov
2021-10-21 3:02 lianzhi chang
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