[patch 3/5] MMC OMAP driver

[patch 3/5] MMC OMAP driver

[Anderson Briglia]

Here are some misc fixes we've had in the OMAP tree. Might be worth
testing them on other platforms too.

Index: linux-2.6.15-mmc_omap/drivers/mmc/mmc.c
===================================================================
--- linux-2.6.15-mmc_omap.orig/drivers/mmc/mmc.c	2006-01-30 10:24:50.000000000 -0400
+++ linux-2.6.15-mmc_omap/drivers/mmc/mmc.c	2006-01-30 10:25:19.000000000 -0400
@@ -704,6 +704,7 @@ static void mmc_power_up(struct mmc_host
 	int bit = fls(host->ocr_avail) - 1;

 	host->ios.vdd = bit;
+	host->ios.clock = host->f_min;
 	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
 	host->ios.chip_select = MMC_CS_DONTCARE;
 	host->ios.power_mode = MMC_POWER_UP;
@@ -712,7 +713,6 @@ static void mmc_power_up(struct mmc_host

 	mmc_delay(1);

-	host->ios.clock = host->f_min;
 	host->ios.power_mode = MMC_POWER_ON;
 	host->ops->set_ios(host, &host->ios);

@@ -747,6 +747,7 @@ static int mmc_send_op_cond(struct mmc_h
 		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
 			break;

+		mmc_delay(1);
 		err = MMC_ERR_TIMEOUT;

 		mmc_delay(10);

Re: [patch 3/5] MMC OMAP driver

[Pierre Ossman]

Anderson Briglia wrote:
> Here are some misc fixes we've had in the OMAP tree. Might be worth
> testing them on other platforms too.
> 
> Index: linux-2.6.15-mmc_omap/drivers/mmc/mmc.c
> ===================================================================
> --- linux-2.6.15-mmc_omap.orig/drivers/mmc/mmc.c	2006-01-30 10:24:50.000000000 -0400
> +++ linux-2.6.15-mmc_omap/drivers/mmc/mmc.c	2006-01-30 10:25:19.000000000 -0400
> @@ -704,6 +704,7 @@ static void mmc_power_up(struct mmc_host
>  	int bit = fls(host->ocr_avail) - 1;
> 
>  	host->ios.vdd = bit;
> +	host->ios.clock = host->f_min;
>  	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
>  	host->ios.chip_select = MMC_CS_DONTCARE;
>  	host->ios.power_mode = MMC_POWER_UP;
> @@ -712,7 +713,6 @@ static void mmc_power_up(struct mmc_host
> 
>  	mmc_delay(1);
> 
> -	host->ios.clock = host->f_min;
>  	host->ios.power_mode = MMC_POWER_ON;
>  	host->ops->set_ios(host, &host->ios);
> 

Why? What you're doing there is enable the clock at the same time as the
 power, instead of just the power first. To me, that seems less safe.

> @@ -747,6 +747,7 @@ static int mmc_send_op_cond(struct mmc_h
>  		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
>  			break;
> 
> +		mmc_delay(1);
>  		err = MMC_ERR_TIMEOUT;
> 
>  		mmc_delay(10);

This seems particularly useless. Probably just a remnant from a separate
mmc_delay() addition to the one that's in mainline now.

Rgds
Pierre

Re: [patch 3/5] MMC OMAP driver

[Russell King]

On Tue, Jan 31, 2006 at 09:37:11AM -0400, Anderson Briglia wrote:
> Here are some misc fixes we've had in the OMAP tree. Might be worth
> testing them on other platforms too.

I've already provided feedback on this a year or so ago - and it
annoys me that absolutely _nothing_ has happened as a result.

The quoted part of this patch is WRONG and will _NEVER_ be merged.
You must NOT enable the clock until the power is stable.  Maybe
this is a cause of the problems that you're seeing with various
cards, since you're not allowing them to reset correctly?

Fix this first, then re-test to see if every other fix you have
is actually necessary.

Sorry, but not following the power up protocol invalidates all other
testing wrt card initialisation behaviour.

> Index: linux-2.6.15-mmc_omap/drivers/mmc/mmc.c
> ===================================================================
> --- linux-2.6.15-mmc_omap.orig/drivers/mmc/mmc.c	2006-01-30 10:24:50.000000000 -0400
> +++ linux-2.6.15-mmc_omap/drivers/mmc/mmc.c	2006-01-30 10:25:19.000000000 -0400
> @@ -704,6 +704,7 @@ static void mmc_power_up(struct mmc_host
>  	int bit = fls(host->ocr_avail) - 1;
> 
>  	host->ios.vdd = bit;
> +	host->ios.clock = host->f_min;
>  	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
>  	host->ios.chip_select = MMC_CS_DONTCARE;
>  	host->ios.power_mode = MMC_POWER_UP;
> @@ -712,7 +713,6 @@ static void mmc_power_up(struct mmc_host
> 
>  	mmc_delay(1);
> 
> -	host->ios.clock = host->f_min;
>  	host->ios.power_mode = MMC_POWER_ON;
>  	host->ops->set_ios(host, &host->ios);
> 

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core