Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression
Hi, On Sun, Nov 13 2011, Subhash Jadavani wrote: Using SD_MODE_UHS_SDR25 macro name is not appropriate here. It's really not the SDR25 mode (although clock rate is 50mhz), it's High speed mode only. Qiang Liu patch had defined new marco SD_MODE_HIGH_SPEED which looks most appropriate to use here. See the version in current mmc-next, it already uses Qiang Liu's macros. Thanks, - Chris. -- Chris Ball c...@laptop.org http://printf.net/ One Laptop Per Child -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH] SD/MMC: fix the issue of SDHC performance regression
-Original Message- From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc- ow...@vger.kernel.org] On Behalf Of Chris Ball Sent: Sunday, November 13, 2011 10:15 PM To: Subhash Jadavani Cc: 'Aaron Lu'; 'Qiang Liu'; linux-mmc@vger.kernel.org; le...@freescale.com; kumar.g...@freescale.com Subject: Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression Hi, On Sun, Nov 13 2011, Subhash Jadavani wrote: Using SD_MODE_UHS_SDR25 macro name is not appropriate here. It's really not the SDR25 mode (although clock rate is 50mhz), it's High speed mode only. Qiang Liu patch had defined new marco SD_MODE_HIGH_SPEED which looks most appropriate to use here. See the version in current mmc-next, it already uses Qiang Liu's macros. Yes, Just checked now. Thanks, Subhash Thanks, - Chris. -- Chris Ball c...@laptop.org http://printf.net/ One Laptop Per Child -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression
On Mon, Nov 07, 2011 at 08:20:10AM -0500, Chris Ball wrote:
Have you seen:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=f2815f68dabbb373fd1c9f0fd4a609d486697c2b
(mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode)
which is already in mainline? I think your patch is identical.
Hi Chris,
I think the existing code is somewhat confusing, since SDR50 means
100MHZ frequency while high speed is 50MHZ.
The reason it is correct is UHS_SDR50_BUS_SPEED is defined as 2,
which happened to be the same value as (1 UHS_SDR25_BUS_SPEED).
How about change it like this:
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index a230e7f..670fd7f 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -306,7 +306,7 @@ static int mmc_read_switch(struct mmc_card *card)
goto out;
}
- if (status[13] UHS_SDR50_BUS_SPEED)
+ if (status[13] SD_MODE_UHS_SDR25)
card-sw_caps.hs_max_dtr = 5000;
if (card-scr.sda_spec3) {
SDR25 is also 50MHZ, the same frequency as high speed.
Or we can add a new macro for high speed like qiang has done,
which one you prefer?
Thanks,
Aaron
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Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression
Hi, On Tue, Nov 08 2011, Aaron Lu wrote: SDR25 is also 50MHZ, the same frequency as high speed. Or we can add a new macro for high speed like qiang has done, which one you prefer? The new macro makes most sense to me -- if no-one disagrees, I'll convert Liu's patch into a rename patch and queue it as a cleanup for 3.2. Thanks! - Chris. -- Chris Ball c...@laptop.org http://printf.net/ One Laptop Per Child -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH] SD/MMC: fix the issue of SDHC performance regression
-Original Message- From: Liu Qiang-B32616 Sent: Monday, November 07, 2011 5:36 PM To: linux-mmc@vger.kernel.org Cc: c...@laptop.org; Li Yang-R58472; Gala Kumar-B11780; Liu Qiang-B32616 Subject: [PATCH] SD/MMC: fix the issue of SDHC performance regression Low performance of SDHC (half of before) due to its frequency was set to 25MHz, but not 50MHz (involved by commit id 013909c4ffd16ded4895528b856fd8782df04dc6, add support for query function modes for uhs cards according to Physical Layer SPEC V3.01). Set high speed max frequency according to response status of CMD6, but not for SPEC Version. Response of switch command is first consideration factor when set SDHC max working frequency. TRAN_SPEED in CSD register will be seemed as the second factor. I'm curious why many SD cards are not setting the clock frequency correctly in the CSD register. Anyone has a clue? - Leo -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression
Hi, On Mon, Nov 07 2011, Qiang Liu wrote: Low performance of SDHC (half of before) due to its frequency was set to 25MHz, but not 50MHz (involved by commit id 013909c4ffd16ded4895528b856fd8782df04dc6, add support for query function modes for uhs cards according to Physical Layer SPEC V3.01). Set high speed max frequency according to response status of CMD6, but not for SPEC Version. Response of switch command is first consideration factor when set SDHC max working frequency. TRAN_SPEED in CSD register will be seemed as the second factor. Signed-off-by: Qiang Liu qiang@freescale.com Have you seen: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=f2815f68dabbb373fd1c9f0fd4a609d486697c2b (mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode) which is already in mainline? I think your patch is identical. Thanks, - Chris. -- Chris Ball c...@laptop.org http://printf.net/ One Laptop Per Child -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH] SD/MMC: fix the issue of SDHC performance regression
-Original Message- From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc-ow...@vger.kernel.org] On Behalf Of Chris Ball Sent: Monday, November 07, 2011 9:20 PM To: Liu Qiang-B32616 Cc: linux-mmc@vger.kernel.org; Li Yang-R58472; Gala Kumar-B11780 Subject: Re: [PATCH] SD/MMC: fix the issue of SDHC performance regression Hi, On Mon, Nov 07 2011, Qiang Liu wrote: Low performance of SDHC (half of before) due to its frequency was set to 25MHz, but not 50MHz (involved by commit id 013909c4ffd16ded4895528b856fd8782df04dc6, add support for query function modes for uhs cards according to Physical Layer SPEC V3.01). Set high speed max frequency according to response status of CMD6, but not for SPEC Version. Response of switch command is first consideration factor when set SDHC max working frequency. TRAN_SPEED in CSD register will be seemed as the second factor. Signed-off-by: Qiang Liu qiang@freescale.com Have you seen: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=f2815f68dabbb373fd1c9f0fd4a609d486697c2b (mmc: sd: Handle SD3.0 cards not supporting UHS-I bus speed mode) which is already in mainline? I think your patch is identical. [Liu Qiang] Yes, they are identical. Thanks a lot. Thanks, - Chris. -- Chris Ball c...@laptop.org http://printf.net/ One Laptop Per Child -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-mmc in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
