lkml.org 
[lkml]   [2015]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mmc: dw_mmc: Don't send clock off command if power is off
Hi,

On 03/23/2015 06:59 AM, Doug Anderson wrote:
> Alim,
>
> On Sun, Mar 22, 2015 at 5:16 AM, Alim Akhtar <alim.akhtar@gmail.com> wrote:
>>> case MMC_POWER_OFF:
>>> - /* Turn clock off before power goes down */
>>> - dw_mci_setup_bus(slot, false);
>>> + /* Turn clock off before power goes down; only if powered */
>>> + if (slot->host->vqmmc_enabled)
>>> + dw_mci_setup_bus(slot, false);
>>>
>> vqmmc_enabled is always _true_ when entering MMC_POWER_OFF case..right?
>> Is this done for extra protection? Or do you have a case where vqmmc
>> is OFF and driver still calls dw_mci_setup_bus from here?
>
> Hmm. I know I got it into the debugger in at least one reboot case
> where it was failing to turn the clock off. I thought I confirmed it
> was the core trying to call MMC_POWER_OFF when the power was already
> off, but now I'm less certain. I looked back at my debug session and
> I don't see where I got that evidence. :-/ Certainly if I put a
> printout here right now I can't see my code making a difference.

I'm not sure this is really needs...and i can't find any error case..

Best Regards,
Jaehoon Chung
>
> Unfortunately the crash was a very rare one, so I may have to go back
> to the drawing board here...
>
> -Doug
>



\
 
 \ /
  Last update: 2015-03-27 09:01    [W:0.054 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site