Regression for non-eMMC cards with commit fa550189?

Hi,

On Tue, May 29, 2012 at 02:52:34PM +0800, Ulf Hansson wrote:

Hi Tony,

This patch changes the sequence of how the host drivers set_ios
function gets called during probe.

Before:
1. mmc_power_off
2. mmc_power_up

Now:
1. mmc_power_up

My guess is then; the omap driver set_ios function requires that
mmc_power_off is called before a mmc_power_up.
Hopefully this requirement can be removed and fixed in the host driver somehow.

Please get back to me if you need some more assistance around this matter.

Kind regards
Ulf Hansson


On 28 May 2012 21:21, Tony Lindgren [off-list ref] wrote:

quoted

Hi Ulf & Chris,

Looks like commit fa550189 (mmc: core: Prevent eMMC VCC supply to be
cut from late init) causes MMC card to stop working at least with
n8x0 using drivers/mmc/host/omap.c. The card(s) on it are not eMMC.

Reverting fa550189 makes things work again. Any ideas what could
be causing this?

No debug output from MMC_DEBUG, looks like commands won't even
get started?

Can you enable debugging on menelaus so we see what the driver is doing ?

I believe that to change the VMMC's supply voltage you need to turn off
the regulator, meaning LDO_CTRL7[1:0] = 0b00.

That could be one thing. It would be cool what menelaus is writing to
the registers on working and failing case. Also what are the contents of
LDO_CTRL1 and LDO_CTRL7 before any operation. Something like this will
help:

diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
index cb4910a..8cab234 100644
--- a/drivers/mfd/menelaus.c
+++ b/drivers/mfd/menelaus.c

@@ -31,6 +31,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#define DEBUG
+
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>

@@ -469,6 +471,10 @@ static int menelaus_set_voltage(const struct menelaus_vtg *vtg, int mV,
 	if (vtg == 0)
 		goto set_voltage;
 
+	dev_dbg(&c->dev, "VTG_REG %02x MODE_REG %02x\n",
+			menelaus_read_reg(vtg->vtg_reg),
+			menelaus_read_reg(mode_reg));
+
 	ret = menelaus_read_reg(vtg->vtg_reg);
 	if (ret < 0)
 		goto out;

-- 
balbi
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