On 6 August 2012 21:01, Chris Ball <cjb@xxxxxxxxxx> wrote: > Hi, > > On Mon, Aug 06 2012, Dirk Behme wrote: >> On embedded devices, often there is a combination of removable mmc >> devices (e.g. MMC/SD cards) and hard wired ones (e.g. eMMC). >> Depending on the hardware configuration, the 'mmcblkN' node might >> change if the removable device is available or not at boot time. >> >> E.g. if the removable device is attached at boot time, it might >> become mmxblk0. And the hard wired one mmcblk1. But if the removable >> device isn't there at boot time, the hard wired one will become >> mmcblk0. This makes it somehow difficult to hard code the root device >> to the non-removable device and boot fast. >> >> This change does simply associate 'N' of 'mmcblkN' with the slot index >> instead of the dynamic name index. The slot index is always the same, >> ensuring that the non-removable mmc device is associated always >> with the same mmcblkN. Independent of the availability of the removable >> one. > > I like this change in principle, but doesn't it break boot for everyone > currently using e.g. root=/dev/mmcblk0p1 on slot index 2? That doesn't > sound like an acceptable regression. > It shouldn't break boot for any user already doing the right thing. If the user's platform probes only slot-2, it will still be 'mmcblk0' If the platform probes slot-1 & 2, it is fundamentally unsafe to count upon the card in slot-2 to be enumerated before the one in slot-1. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
