On 09/02/2014 05:31 PM, Peter A. Bigot wrote:
The capacity and lba for an MMC device with part_num 0 reflects the whole device. When mmc_switch_part() successfully switches to a partition, the capacity is changed to that partition. As partition 0 does not physically exist, attempts to switch back to the whole device will indicate an error, but the capacity setting for the whole device must still be restored to match the partition.
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
@@ -594,10 +594,15 @@ int mmc_switch_part(int dev_num, unsigned int part_num) ret = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF, (mmc->part_config & ~PART_ACCESS_MASK) | (part_num & PART_ACCESS_MASK));
if (ret)
return ret;return mmc_set_capacity(mmc, part_num);
- /*
* Set the capacity if the switch succeeded or was intended* to return to representing the raw device.*/- if ((ret == 0) || ((ret == -ENODEV) && (part_num == 0)))
ret = mmc_set_capacity(mmc, part_num);- return ret; }
I think this wouldn't be needed without patch 1/2, since without that patch, no partition switching should ever happen if HW partitions don't exist, and hence this patch shouldn't be required.