From: kishore kadiyala <kishorek.kadiyala@gmail.com> To: Madhusudhan <madhu.cr@ti.com> Cc: Vimal Singh <vimal.newwork@gmail.com>, tony@atomide.com, svenkatr@ti.com, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, jarkko.lavinen@nokia.com Subject: [PATCH v3] OMAP: Fix for bus width which improves SD card's peformance. Date: Mon, 5 Apr 2010 18:26:16 +0530 [thread overview] Message-ID: <m2n7f9d1ffb1004050556o1ed2eec8ief66d60fc85f96de@mail.gmail.com> (raw) In-Reply-To: <003c01cad1b1$da2cdbf0$544ff780@am.dhcp.ti.com> 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> Tested-by: Jarkko Nikula <jhnikula@gmail.com> --- In V3 : Updated with Madhu's comments and appended Tested by Nikula 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(-) drivers/mmc/host/omap_hsmmc.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 83f0aff..44e79f7 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -2091,9 +2091,9 @@ static int __init omap_hsmmc_probe(struct mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED | MMC_CAP_WAIT_WHILE_BUSY; - if (mmc_slot(host).wires >= 8) - mmc->caps |= MMC_CAP_8_BIT_DATA; - else if (mmc_slot(host).wires >= 4) + if (mmc_slot(host).wires == 8) + 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; if (mmc_slot(host).nonremovable) -- 1.6.3.3
WARNING: multiple messages have this Message-ID (diff)
From: kishore kadiyala <kishorek.kadiyala@gmail.com> To: Madhusudhan <madhu.cr@ti.com> Cc: Vimal Singh <vimal.newwork@gmail.com>, tony@atomide.com, svenkatr@ti.com, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, jarkko.lavinen@nokia.com Subject: [PATCH v3] OMAP: Fix for bus width which improves SD card's peformance. Date: Mon, 5 Apr 2010 18:26:16 +0530 [thread overview] Message-ID: <m2n7f9d1ffb1004050556o1ed2eec8ief66d60fc85f96de@mail.gmail.com> (raw) In-Reply-To: <003c01cad1b1$da2cdbf0$544ff780@am.dhcp.ti.com> 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> Tested-by: Jarkko Nikula <jhnikula@gmail.com> --- In V3 : Updated with Madhu's comments and appended Tested by Nikula 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(-) drivers/mmc/host/omap_hsmmc.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 83f0aff..44e79f7 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -2091,9 +2091,9 @@ static int __init omap_hsmmc_probe(struct mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED | MMC_CAP_WAIT_WHILE_BUSY; - if (mmc_slot(host).wires >= 8) - mmc->caps |= MMC_CAP_8_BIT_DATA; - else if (mmc_slot(host).wires >= 4) + if (mmc_slot(host).wires == 8) + 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; if (mmc_slot(host).nonremovable) -- 1.6.3.3
next prev parent reply other threads:[~2010-04-05 12:56 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-11 14:20 [PATCH] OMAP: Fix for bus width which improves SD card's peformance kishore kadiyala 2010-02-11 14:20 ` kishore kadiyala 2010-02-11 17:34 ` Madhusudhan 2010-02-11 17:34 ` Madhusudhan 2010-03-31 6:07 ` [PATCH-V2] " kishore kadiyala 2010-03-31 6:07 ` kishore kadiyala 2010-03-31 6:27 ` Vimal Singh 2010-03-31 6:27 ` Vimal Singh 2010-03-31 7:03 ` kishore kadiyala 2010-03-31 7:03 ` kishore kadiyala 2010-03-31 13:11 ` Jarkko Nikula 2010-03-31 13:11 ` Jarkko Nikula 2010-03-31 16:37 ` Madhusudhan 2010-03-31 16:37 ` Madhusudhan 2010-04-01 6:31 ` kishore kadiyala 2010-04-01 6:31 ` kishore kadiyala 2010-04-01 15:41 ` Madhusudhan 2010-04-01 15:41 ` Madhusudhan 2010-04-05 12:56 ` kishore kadiyala [this message] 2010-04-05 12:56 ` [PATCH v3] " kishore kadiyala 2010-04-05 16:48 ` Felipe Balbi 2010-04-05 17:19 ` Madhusudhan 2010-04-05 17:19 ` Madhusudhan 2010-04-05 17:43 ` Madhusudhan 2010-04-05 17:43 ` Madhusudhan 2010-04-06 5:00 ` Felipe Balbi 2010-04-06 16:16 ` Madhusudhan 2010-04-06 16:16 ` Madhusudhan 2010-04-06 16:32 ` Felipe Balbi 2010-04-06 16:55 ` Nishanth Menon 2010-04-06 16:57 ` Felipe Balbi 2010-04-06 23:23 ` Madhusudhan 2010-04-06 23:23 ` Madhusudhan 2010-04-06 23:39 ` Nishanth Menon 2010-04-07 0:16 ` Madhusudhan 2010-04-07 0:16 ` Madhusudhan 2010-04-07 0:57 ` Nishanth Menon 2010-04-08 16:57 ` Madhusudhan 2010-04-08 16:57 ` Madhusudhan 2010-04-19 15:36 ` [PATCH v4] " kishore kadiyala 2010-04-19 15:36 ` kishore kadiyala 2010-04-19 15:51 ` kishore kadiyala 2010-04-19 15:51 ` kishore kadiyala 2010-04-22 0:26 ` Madhusudhan 2010-04-22 0:26 ` Madhusudhan 2010-06-14 16:10 ` [PATCH v5] " kishore kadiyala 2010-06-15 8:04 ` kishore kadiyala 2010-06-15 8:07 ` kishore kadiyala 2010-06-30 14:59 ` kishore kadiyala 2010-07-07 14:15 ` kishore kadiyala
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