[RFC] improve mmc init sequence

[RFC] improve mmc init sequence

[Shawn Lin]

Hello Ulf,
	I notice we add MMC_CAP2_NO_SDIO to avoid sending sdio commands during 
initialization. So that means we can use it to improve mmc init
sequence if a specific board use one slot just for emmc or sd. But I 
realize that we can move a step further to add more cap2 like NO_SD/
NO_MMC in order to reduce the boot time. Does that make sense? If the
answer is *yes*, I am happy to push some patches for it since I have
been doing it on my local tree and testing for a long time.

-- 
Best Regards
Shawn Lin

Re: [RFC] improve mmc init sequence

[Ulf Hansson]

On 17 March 2016 at 04:41, Shawn Lin <shawn.lin@rock-chips.com> wrote:
> Hello Ulf,
>         I notice we add MMC_CAP2_NO_SDIO to avoid sending sdio commands
> during initialization. So that means we can use it to improve mmc init
> sequence if a specific board use one slot just for emmc or sd. But I realize
> that we can move a step further to add more cap2 like NO_SD/
> NO_MMC in order to reduce the boot time. Does that make sense? If the
> answer is *yes*, I am happy to push some patches for it since I have
> been doing it on my local tree and testing for a long time.

I am not against it, so please go ahead!

Although, you need to give some proof of the amount of saved boot time
(or better the decreased initialization time of a couple of different
cards).

Kind regards
Uffe

Re: [RFC] improve mmc init sequence

[Jaehoon Chung]

On 03/17/2016 07:43 PM, Ulf Hansson wrote:
> On 17 March 2016 at 04:41, Shawn Lin <shawn.lin@rock-chips.com> wrote:
>> Hello Ulf,
>>         I notice we add MMC_CAP2_NO_SDIO to avoid sending sdio commands
>> during initialization. So that means we can use it to improve mmc init
>> sequence if a specific board use one slot just for emmc or sd. But I realize
>> that we can move a step further to add more cap2 like NO_SD/
>> NO_MMC in order to reduce the boot time. Does that make sense? If the
>> answer is *yes*, I am happy to push some patches for it since I have
>> been doing it on my local tree and testing for a long time.
> 
> I am not against it, so please go ahead!
> 
> Although, you need to give some proof of the amount of saved boot time
> (or better the decreased initialization time of a couple of different
> cards).

I have already tested with similar sequence..I have remembered there is a benefit for decreasing the booting time.
But i didn't remember how much time is decreased...because it wast too long time ago.

Best Regards,
Jaehoon Chung

> 
> Kind regards
> Uffe
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