From: jh80.chung@samsung•com (Jaehoon Chung)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] mmc: dw_mmc: Don't send clock off command if power is off
Date: Fri, 27 Mar 2015 16:21:09 +0900 [thread overview]
Message-ID: <551504E5.7060304@samsung.com> (raw)
In-Reply-To: <CAD=FV=VUG54vk9xD9zEnaP_rQcL4cWLOHuy76aMRta0OOsLn1g@mail.gmail.com>
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
>
prev parent reply other threads:[~2015-03-27 7:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-20 18:00 [PATCH] mmc: dw_mmc: Don't send clock off command if power is off Doug Anderson
2015-03-22 12:16 ` Alim Akhtar
2015-03-22 21:59 ` Doug Anderson
2015-03-27 7:21 ` Jaehoon Chung [this message]
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