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Revert "mmc: retry the cmd8 to meet 74 clocks requirement in the spec"

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This reverts commit 02f3029f18.

This patch add 3 times retry to CMD8 because the Marvell mmc controller
doesn't obey the power ramp up process in the SD specification 6.4.1.
(Please refer to figure 6.1 and 6.2 in the specification.)

The CMD0 should be send after power ramp up has been finished.
However, the Marvell mmc contorller must do power ramp up after the
first CMD0 command has been send.

This patch also affect existing platforms like Nokia N900 and other
platforms.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
Acked-by: Lei Wen <leiwen@marvell.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Macpaul Lin 2011-11-14 23:35:39 +00:00 committed by Andy Fleming
parent 5af9a56999
commit afd5932b2c
1 changed files with 2 additions and 14 deletions
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16
drivers/mmc/mmc.c
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@ -1190,7 +1190,7 @@ block_dev_desc_t *mmc_get_dev(int dev)
int mmc_init(struct mmc *mmc)
{
int err, retry = 3;
int err;
if (mmc->has_init)
return 0;
@ -1213,19 +1213,7 @@ int mmc_init(struct mmc *mmc)
mmc->part_num = 0;
/* Test for SD version 2 */
/*
* retry here for 3 times, as for some controller it has dynamic
* clock gating, and only toggle out clk when the first cmd0 send
* out, while some card strictly obey the 74 clocks rule, the interval
* may not be sufficient between the cmd0 and this cmd8, retry to
* fulfil the clock requirement
*/
do {
err = mmc_send_if_cond(mmc);
} while (--retry > 0 && err);
if (err)
return err;
err = mmc_send_if_cond(mmc);
/* Now try to get the SD card's operating condition */
err = sd_send_op_cond(mmc);