Re: [U-Boot] [PATCH] powerpc/esdhc: force the bus width to 4bit
Dear Huang Changming-R66093,
Fixing the ML address ... and reposting the rest.
Andy, Do you agree my suggest to revert these codes to fix this issue?
Please ... do us all a favor, read [1] and stop being so inconsiderate of others! Given that I can no longer make any sense of this thread because of your top-posting making it complete utmost mess, my opinion is NAK on reverting them.
[1] http://www.ietf.org/rfc/rfc1855.txt
Best Regards Jerry Huang
-----Original Message----- From: u-boot-bounces@linux.freescale.net [mailto:u-boot- bounces@linux.freescale.net] On Behalf Of Huang Changming-R66093 Sent: Wednesday, October 31, 2012 10:08 AM To: Andy Fleming; Marek Vasut Cc: u-boot@linux.freescale.net Subject: Re: [u-boot] [PATCH] powerpc/esdhc: force the bus width to 4bit
Below is the old codes (width = 2):
} else {
for (width = EXT_CSD_BUS_WIDTH_8; width >= 0; width--) {the current codes for MMC card has been changed to:
} else {
width = ((mmc->host_caps & MMC_MODE_MASK_WIDTH_BITS) >>
MMC_MODE_WIDTH_BITS_SHIFT);for (; width >= 0; width--) { ....
FSL ESDHC driver set the host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT; So for FSL ESDHC, the width = 3, after implement mmc_switch successfully, will set the bus to 4 * width. Therefore, I will get the 12bit (4 x 3) bus width.
I don't know why do this modification? If to fix the stack bug, then I need to revert these codes. Andy, do you agree it?
Best Regards Jerry Huang
-----Original Message----- From: Andy Fleming [mailto:afleming@gmail.com] Sent: Tuesday, October 30, 2012 10:34 PM To: Marek Vasut Cc: Huang Changming-R66093; u-boot@linux.freescale.net Subject: Re: [PATCH] powerpc/esdhc: force the bus width to 4bit
On Oct 30, 2012, at 5:50, Marek Vasut marex@denx.de wrote:
Dear Chang-Ming.Huang@freescale.com,
From: Jerry Huang Chang-Ming.Huang@freescale.com
For the current u-boot codes, only 4bit/1bit SD/SDHC bus width is
support.
So for MMC card, we also support 4bit bus width, otherwiase, we will
get the 12bit bus width, which is not correct:
[...]
--- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -577,7 +577,7 @@ int fsl_esdhc_initialize(bd_t *bis, struct fsl_esdhc_cfg *cfg) return -1;
}
- mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT;
- mmc->host_caps = MMC_MODE_4BIT;
This fix is not correct, fix the MMC subsystem please.
Agreed. Bit width just needs smarter printing. Unless this patch is
doing
more than ensuring the printout is correct
Andy
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Marek Vasut