[3/3] mmc: use SD/MMC host ID for block device name ID
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Message ID 1461884805-29466-4-git-send-email-dianders@chromium.org
State New
Headers show

Commit Message

Douglas Anderson April 28, 2016, 11:06 p.m. UTC
From: Stefan Agner <stefan@agner.ch>

By using the SD/MMC host device ID as a starting point for block
device numbering, one can reliably predict the first block device
name (at least for the first controller). This is especially useful
for SoCs with multiple SD/MMC host controller, where the controller
with index 0 is connected to a eMMC device.

Usually the first controller gets the first block device name ID,
however this is not guaranteed. Also if the first controller is
aliased as second controller and visa-versa (using device tree
aliases), the block device name ID assignation is not ordered by
the SD/MMC host device ID (since mmc_rescan is called in order of
the memory mapped pheripherial addresses).

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 drivers/mmc/card/block.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch
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diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 9fef7f04c4e6..bcf4fdbb5221 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -2215,7 +2215,8 @@  static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	 * index anymore so we keep track of a name index.
 	 */
 	if (!subname) {
-		md->name_idx = find_first_zero_bit(name_use, max_devices);
+		md->name_idx = find_next_zero_bit(name_use, max_devices,
+				card->host->index);
 		__set_bit(md->name_idx, name_use);
 	} else
 		md->name_idx = ((struct mmc_blk_data *)