powerpc/esdhc: force the bus width to 4bit

Andy,
Do you agree my suggest to revert these codes to fix this issue?

Best Regards
Jerry Huang

Quoted 82 lines

-----Original Message-----
From: u-boot-bounces at linux.freescale.net [mailto:u-boot- bounces at 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 at 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

Quoted 26 lines

-----Original Message-----
From: Andy Fleming [mailto:afleming at gmail.com]
Sent: Tuesday, October 30, 2012 10:34 PM
To: Marek Vasut
Cc: Huang Changming-R66093; u-boot at linux.freescale.net
Subject: Re: [PATCH] powerpc/esdhc: force the bus width to 4bit

Quoted 5 lines · Marek Vasut

Dear Chang-Ming.Huang at freescale.com,

Quoted 3 lines

From: Jerry Huang <[email protected]>

For the current u-boot codes, only 4bit/1bit SD/SDHC bus width is

support.

Quoted 10 lines

Quoted 3 lines

So for MMC card, we also support 4bit bus width, otherwiase, we will

get the 12bit bus width, which is not correct:

[...]

Quoted 5 lines

drivers/mmc/fsl_esdhc.c +0 -0

@@ -577,7 +577,7 @@ int fsl_esdhc_initialize(bd_t *bis, struct
 fsl_esdhc_cfg *cfg) return -1;
 

Quoted 8 lines

Quoted 6 lines

drivers/mmc/fsl_esdhc.c int fsl_esdhc_initialize(bd_t *bis, struct · line 581

Quoted 4 lines

drivers/mmc/fsl_esdhc.c +1 -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

Quoted 3 lines

more than ensuring the printout is correct

Andy

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Best Regards
Jerry Huang

Quoted 18 lines

-----Original Message-----
From: Marek Vasut [mailto:marex at denx.de]
Sent: Thursday, November 01, 2012 10:26 AM
To: Huang Changming-R66093
Cc: Andy Fleming; u-boot at linux.freescale.net
Subject: Re: [PATCH] powerpc/esdhc: force the bus width to 4bit

Dear Huang Changming-R66093,

Quoted 2 lines

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.

Quoted 1 line

[1] http://www.ietf.org/rfc/rfc1855.txt

Then, could you give some suggest, how to fix the 12bit-width issue?

-----Original Message-----
From: Marek Vasut [mailto:marex at denx.de]
Sent: Thursday, November 01, 2012 11:06 AM
To: Huang Changming-R66093
Cc: Andy Fleming; u-boot at linux.freescale.net; u-boot at lists.denx.de
Subject: Re: [PATCH] powerpc/esdhc: force the bus width to 4bit

Dear Huang Changming-R66093,

Reposting _AGAIN_ because you again discarded the U-Boot ML address.

Quoted 13 lines

Quoted 13 lines

-----Original Message-----
From: Marek Vasut [mailto:marex at denx.de]
Sent: Thursday, November 01, 2012 10:26 AM
To: Huang Changming-R66093
Cc: Andy Fleming; u-boot at linux.freescale.net
Subject: Re: [PATCH] powerpc/esdhc: force the bus width to 4bit

Dear Huang Changming-R66093,

Quoted 2 lines

Andy,
Do you agree my suggest to revert these codes to fix this issue?

Quoted 8 lines

Quoted 6 lines

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

Then, could you give some suggest, how to fix the 12bit-width issue?

see drivers/mmc/mmc.c:

1089 width = ((mmc->host_caps & MMC_MODE_MASK_WIDTH_BITS) >>
1090 MMC_MODE_WIDTH_BITS_SHIFT);

Fix this snipped of code and the related code below ... that's the way to go about it.