[U-Boot] [PATCH 3/4] MMC Multi-block Support

[Steve Sakoman]

On Sat, Oct 23, 2010 at 8:14 AM, Ghorai, Sukumar <s-ghorai at ti.com> wrote:
>
>
>> -----Original Message-----
>> From: u-boot-bounces at lists.denx.de [mailto:u-boot-bounces at lists.denx.de]
>> On Behalf Of Steve Sakoman
>> Sent: Friday, October 15, 2010 3:14 AM
>> To: John Rigby
>> Cc: u-boot at lists.denx.de; Alagu Sankar; Andy Fleming
>> Subject: Re: [U-Boot] [PATCH 3/4] MMC Multi-block Support
>>
>> On Mon, Oct 4, 2010 at 1:32 PM, John Rigby <jcrigby at gmail.com> wrote:
>> > Alagu,
>> >
>> > This never made it into Andy's tree nor upstream.  Could you submit a
>> > new patch to current upstream with the config option removed as Andy
>> > said he did back in May?  Maybe we can get it commited via some other
>> > maintainer.  Steve Sakoman seems to have done some MMC work lately.
>>
>> I've done some testing with this patch on OMAP3 and OMAP4, in the
>> "always enabled" version.
>>
>> I compared the old legacy mmc driver vs the new generic mmc driver vs
>> new generic mmc driver with multiblock read support added.
>>
>> The good news is that the generic mmc driver for OMAP is almost twice
>> as fast as the old legacy driver.  These patches should be in the next
>> u-boot-ti pull request and so will be in mainline shortly.
>>
>> The bad news is that multiblock reads seem to make no difference :-(
>>
>> For reading a 45MB file from an ext3 partition using ext2load I get:
>>
>> legacy:              62 seconds
>> generic:             35 seconds
>> generic w/ multi: 35 seconds
>>
>> I'm happy to resubmit the multi-block read patch because it does seem
>> to work properly and may even yield improvements on other
>> architectures.
>>
>> Would you like me to do that?

> [Ghorai]
> would you please try with additional change?

Yes! That is much better!

Now multiblock reads are faster :-)

The results (including the old legacy mmc driver for reference):

legacy:              62 seconds
generic:             35 seconds
generic w/ multi: 9 seconds

I will add my "Acked-by" and "Tested-by" and submit the final patch to
the list later today.

Steve


> $>git diff drivers/mmc/omap_hsmmc.c
>
> diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
> index f8b9840..7f3f968 100644
> --- a/drivers/mmc/omap_hsmmc.c
> +++ b/drivers/mmc/omap_hsmmc.c
> @@ -401,6 +401,7 @@ int omap_mmc_init(int dev_index)
>
>        mmc->f_min = 400000;
>        mmc->f_max = 52000000;
> +       mmc->b_max = 0xFFFF;
>
>        mmc_register(mmc);
>
>>
>> Steve
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>