> -----Original Message----- > From: kishore kadiyala [mailto:kishore.kadiyala@xxxxxx] > Sent: Thursday, February 11, 2010 8:20 AM > To: linux-omap@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Cc: jarkko.lavinen@xxxxxxxxx; madhu.cr@xxxxxx > Subject: [PATCH] OMAP: Fix for bus width which improves SD card's > peformance. > > 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 peformance. > This patch fixes the issue and improves the performance of > SD cards. > > Signed-off-by: Kishore Kadiyala <kishore.kadiyala@xxxxxx> ACK Acked-by: Madhusudhan Chikkature <madhu.cr@xxxxxx> > --- > 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 > platform_device > *pdev) > 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; > > -- > 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
