Messages in this thread | | | From | "Madhusudhan" <> | Subject | RE: [PATCH-V2] OMAP: Fix for bus width which improves SD card's peformance. | Date | Wed, 31 Mar 2010 11:37:19 -0500 |
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> -----Original Message----- > From: kishore kadiyala [mailto:kishorek.kadiyala@gmail.com] > Sent: Wednesday, March 31, 2010 2:03 AM > To: Vimal Singh > Cc: Madhusudhan; tony@atomide.com; svenkatr@ti.com; linux- > omap@vger.kernel.org; linux-kernel@vger.kernel.org; > jarkko.lavinen@nokia.com > Subject: Re: [PATCH-V2] OMAP: Fix for bus width which improves SD card's > peformance. > > Sorry for that and here's the Updated one. > > From: Kishore Kadiyala <kishore.kadiyala@ti.com> > > This patch improves low speeds for SD cards. > OMAP-MMC controller's can support maximum bus width of '8'. > when bus width is mentioned as "8" in controller data,the SD > stack will check whether bus width is "4" and if not it will > set bus width to "1" and there by degrading performance. > This patch fixes the issue and improves the performance of > SD cards. > > Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com> > Signed-off-by: Venkatraman S <svenkatr@ti.com> > Acked-by: Madhusudhan Chikkature <madhu.cr@ti.com> > > --- > In V2 : Appended Signed-off by Venkat and Ack by Madhu > > Here are my experiment numbers, on a Class 6 SDHC card: > Read peformance is increased by 220% > Write Performance is increased by 52% > > drivers/mmc/host/omap_hsmmc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 83f0aff..8c97c22 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -2092,7 +2092,7 @@ static int __init omap_hsmmc_probe(struct > MMC_CAP_WAIT_WHILE_BUSY; > > if (mmc_slot(host).wires >= 8) > - mmc->caps |= MMC_CAP_8_BIT_DATA; > + mmc->caps |= (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA); > else if (mmc_slot(host).wires >= 4) > mmc->caps |= MMC_CAP_4_BIT_DATA; > Kishore,
Since this patch is not yet pushed it makes sense to fix the readability issue.
Since 8-bit is the max how about:
if (mmc_slot(host).wires == 8) mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA; if (mmc_slot(host).wires == 4) mmc->caps |= MMC_CAP_4_BIT_DATA;
This would be little easy to read the code.
Can you please repost the patch??
Regards, Madhu
> -- > 1.6.3.3
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