[PATCH v2 3/4] mmc: use SD/MMC host ID for block device name ID

Douglas Anderson dianders at chromium.org
Fri Apr 29 10:32:18 PDT 2016

From: Stefan Agner <stefan at 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 at agner.ch>
Signed-off-by: Douglas Anderson <dianders at chromium.org>
Changes in v2:
- Rebased atop mmc-next

 drivers/mmc/card/block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 9ce679255775..360700f3e0ea 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -2197,7 +2197,7 @@ again:
 		return ERR_PTR(-ENOMEM);
-	ret = ida_get_new(&mmc_blk_ida, &devidx);
+	ret = ida_get_new_above(&mmc_blk_ida, card->host->index, &devidx);
 	if (ret == -EAGAIN)

More information about the Linux-rockchip mailing list