This series picks patches from various different places to produce what I consider the best solution to getting consistent mmc and mmcblk ordering.
Why consistent ordering and why not just use UUIDs? IMHO consistent ordering solves a few different problems: 1. For poor, feeble-minded humans like me, have sane numbering for devices helps a lot. When grepping through dmesg it's terribly handy if a given SDMMC device has a consistent number. I know that I can do "dmesg | grep mmc0" or "dmesg | grep mmcblk0" to find info about the eMMC. I know that I can do "dmesg | grep mmc1" to find info about the SD card slot. I don't want it to matter which one probed first, I don't want it to matter if I'm working on a variant of the hardware that has the SD card slot disabled, and I don't want to care what my boot device was. Worrying about what device number I got increases my cognitive load. 2. There are cases where it's not trivially easy during development to use the UUID. Specifically I work a lot with coreboot / depthcharge as a BIOS. When configured properly, that BIOS has a nice feature to allow you to fetch the kernel and kernel command line from TFTP by pressing Ctrl-N. In this particular case the BIOS doesn't actually know which disk I'd like for my root filesystem, so it's not so easy for it to put the right UUID into the command line. For this purpose, knowing that "mmcblk0" will always refer to eMMC is handy. Jaehoon Chung (1): Documentation: mmc: Document mmc aliases Stefan Agner (2): mmc: read mmc alias from device tree mmc: use SD/MMC host ID for block device name ID Documentation/devicetree/bindings/mmc/mmc.txt | 11 +++++++++++ drivers/mmc/card/block.c | 3 ++- drivers/mmc/core/host.c | 25 ++++++++++++++++++++----- 3 files changed, 33 insertions(+), 6 deletions(-) -- 2.8.0.rc3.226.g39d4020
