USB/mmc rootfs conflict - vexpress
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-linaro (Ubuntu) |
Invalid
|
Medium
|
Matt Waddel | ||
linux-linaro-vexpress (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
Bug Description
If I mount the rootfs on the USB drive I get thousands of
errors related to the SD card like those seen below. After
booting I cannot mount the SD card partitions.
If I mount the same rootfs on the SD device first everything
works without errors.
---
Linux version 2.6.35-
...
mmcblk0: error -5 transferring data, sector 3964802, nr 6, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964802
Buffer I/O error on device mmcblk0, logical block 495600
mmcblk0: error -5 transferring data, sector 3964807, nr 1, card status 0x900
end_request: I/O error, dev mmcblk0, sector 3964807
Buffer I/O error on device mmcblk0, logical block 495600
mmcblk0: error -5 transferring data, sector 3964915, nr 5, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964915
Buffer I/O error on device mmcblk0, logical block 495614
mmcblk0: error -5 transferring data, sector 3964913, nr 7, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964913
mmcblk0: error -5 transferring data, sector 3964914, nr 6, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964914
Buffer I/O error on device mmcblk0, logical block 495614
mmcblk0: error -5 transferring data, sector 8, nr 8, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 8
mmcblk0: error -5 transferring data, sector 9, nr 7, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 9
mmcblk0: error -110 sending read/write command, response 0xb00, card
status 0x400b00
end_request: I/O error, dev mmcblk0, sector 10
mmcblk0: error -110 sending read/write command, response 0x400b00, card
status 0x400b00
end_request: I/O error, dev mmcblk0, sector 11
mmcblk0: error -5 transferring data, sector 3964665, nr 7, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964665
Buffer I/O error on device mmcblk0, logical block 495583
mmcblk0: error -5 transferring data, sector 3964677, nr 3, card status 0xb00
end_request: I/O error, dev mmcblk0, sector 3964677
Buffer I/O error on device mmcblk0, logical block 495584
...
tags: | added: armel vexpress |
Changed in linux-linaro (Ubuntu): | |
importance: | Undecided → Medium |
assignee: | nobody → Matt Waddel (mwaddel) |
Changed in linux-linaro (Ubuntu): | |
status: | New → Confirmed |
Changed in linux-linaro-vexpress (Ubuntu): | |
status: | New → Confirmed |
Changed in linux-linaro (Ubuntu): | |
status: | Confirmed → Invalid |
Changed in linux-linaro-vexpress (Ubuntu): | |
status: | Confirmed → Invalid |
I did some further investigations...
1. MMC access are generally terribly slow - 45-50 kB/s writes, 60-65 kB/s reads. Expected value at least in hundreds kB/s - normal cards have maximum throughput at least 1 MB/s, premium cards up to 5-10 MB/s!
2. USB accesses performed at the same time as MMC ones generate MMC errors.
3. Reducing MMC clock frequency ("mmci. fmax=1900000" ) reduces number of errors, for the price of slowing down (even more!) transfers.
4. Two possible sources of problem are: a bug in driver or underlying hardware (VE motherboard peripherals FPGA) problem, with the latter more probable (as the driver is used - presumably with success - in field).
Due to lack of time here, I'll have to pass the issue to ARM support team.