Re: [PATCH] pl011: added clock management feature

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Nov 9, 2010 at 11:40 PM, Greg KH <greg@xxxxxxxxx> wrote:
> On Tue, Nov 09, 2010 at 04:30:37PM +0100, Linus Walleij wrote:
>> From: Grzegorz Sygieda <grzegorz.sygieda@xxxxxxxxx>
>>
>> This patch allows to control the pl011 clock using set_termios
>> callback. Any positive baudrate passed enables clock, otherwise
>> disables. This saves a lot of power on submicron designs since
>> we can clock off and disable unused UARTs.
>
> That's nice, but it seems like an overload of what people traditionally
> think of when it comes to baud rates.  Why not just power down ports
> that are not open instead?

I like the idea as well and this is definitely gonna help conserving
the power for Bluetooth UARTs.

But using baud rate 0 is something I don't like. Why don't you stop
the clocks if RTS is cleared? This would have allowed the line
discipline driver to implicitly control the UART clock and there will
be no risk of losing data, as well as no non-standard behavior
involved. In fact, you'll be transparent to the upper layers in this
case.

~Vitaly
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux PPP]     [Linux FS]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Linmodem]     [Device Mapper]     [Linux Kernel for ARM]

  Powered by Linux