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[Components] sdio: try bus width depends on host's capability 

It makes no sense to try bus width if not supported by drivers or BSP,
since we know it must be failed. It saves a lot for booting in time
critical environment.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
This commit is contained in:
Shawn Lin 2020-03-12 08:52:56 +08:00
parent a33bc0f321
commit 11277014a3
1 changed files with 10 additions and 1 deletions
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11
components/drivers/sdio/mmc.c
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@ -318,8 +318,17 @@ static int mmc_select_bus_width(struct rt_mmcsd_card *card, rt_uint8_t *ext_csd)
* the device to work in 8bit transfer mode. If the * the device to work in 8bit transfer mode. If the
* mmc switch command returns error then switch to * mmc switch command returns error then switch to
* 4bit transfer mode. On success set the corresponding * 4bit transfer mode. On success set the corresponding
* bus width on the host. * bus width on the host. Meanwhile, mmc core would
* bail out early if corresponding bus capable wasn't
* set by drivers.
*/ */
if ((!(host->flags & MMCSD_BUSWIDTH_8) &&
ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_8) ||
(!(host->flags & MMCSD_BUSWIDTH_4) &&
(ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_4 ||
ext_csd_bits[idx] == EXT_CSD_BUS_WIDTH_8)))
continue;
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH,
ext_csd_bits[idx]); ext_csd_bits[idx]);