[HTC Sensation] RayeR:
Hi,

after my 1st HTC Sensation XE died on bad eMMC chip (probably due to BGA soldering) I got a replacement with broken display so I swapped the CPU board. But after S-OFF and flashing TWRP 2.8.6.0 I experienced the same problem with unable to mount/format the /data partition as you guys. In dmesg log I can see some eMMC errors...

<3>[ 533.994835] mmc_blk_issue_rq failed!!
<6>[ 533.995414] mmc0: Controller has been reinitialized
<3>[ 534.006004] mmcblk0: error -110 sending status comand
<3>[ 534.006157] mmcblk0: error -110 sending read/write command, response 0x0, card status 0x0
<3>[ 534.038505] mmcblk0: error -110 requesting status
<3>[ 534.038627] end_request: I/O error, dev mmcblk0, sector 4426595
<3>[ 534.038780] end_request: I/O error, dev mmcblk0, sector 4426597
<3>[ 534.038871] end_request: I/O error, dev mmcblk0, sector 4426599
<3>[ 534.038963] end_request: I/O error, dev mmcblk0, sector 4426601
...

After I found this thread I tried to flash Ivanich TWRP 3.0.0-R4 and reformat /data and /cache with F2FS. It wend quickly, mount was OK and I can flash CM12 ROM from SD but it hangs at boot-logo as you describd too. I then try format back to EXT4 with suggested command:

but it hangs. How long it should execute normally?

mke2fs -T ext4 /dev/block/mmcblk0p23

mke2fs 1.42.9 (28-Dec-2013)

Discarding device blocks: 4096/305852

its about 15 minutes and still nothing. Giving up after sleepless night :(

What is the problem with F2FS? Is Ivanich CM12 from 2016/03 ready to use F2FS?

If it cannot be fixed how I can modify the mountpoint to use /data on my SD? (I would split it to one FAT and one EXT4 partition)

EDIT: it finished finally...

mke2fs -T ext4 /dev/block/mmcblk0p23
mke2fs 1.42.9 (28-Dec-2013)
Discarding device blocks: failed - I/O error
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
76480 inodes, 305852 blocks
15292 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=314572800
10 block groups
32768 blocks per group, 32768 fragments per group
7648 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912

Allocating group tables: done
Warning: could not read block 0: Attempt to read block from filesystem resulted
in short read
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done

but /data still cannot be mounted :(

EDIT2: I must also note, that after CPU board replacement the phone was working with original ROM Android 4.0.3 and I was able to do factory reset so /data partition was OK. It messed up after I S-OFF and flashed the TWRP 2.8.6.0 and run wipe there.

Isnn't there some low-level format utility for eMMC that would trigger chip erase and also did a bad block remapping? I also wonder why other partitions are OK and just data have problem. I would expect that wear-levelling algo. could replace bad sectors over entire chip. Maybe it would help to shrink the /data partition and leave some unallocated space?

EDIT3: after /data formating it even gets worse, I cannot run recovery properly> TWRP 2.8.6.0 restarts GUI every ~1s but I can connect with ADB and run commands. TWRP3.0.0 restarts the device in a loop. CWM doesn't display GUI and hangs. I don't know what happened, in fastboot mode I still can reflash the recovery image but it doesn't fix it. So only HBOOT remain working....