Comment 36 for bug 366478

Revision history for this message
Antonio Ospite (ospite) wrote :

Hi, I think I solved the problem here, maybe this can help the others who are experiencing it.

The hardware:
058f:6362 Alcor Micro Corp. Flash Card Reader/Writer

it used to work in the past but after a software upgrade it stopped working.

The problem:
the hardware was recognized (I could see the card reader in dmesg) but mass storage devices where not scanned automatically on insertion, and hence partitions where not found and mounted automatically.

The workaround:
Inserting a memory card showed nothing, but if I removed the usb_storage module and loaded it again leaving the memory card inserted, the device was scanned and the partition mounted.

The analysis:
So the hardware worked and the kernel driver worked too to some extent, just scanning at insertion time was broken.

A possible solution:
Enable polling like described in http://forums.funtoo.org/viewtopic.php?id=2243

$ echo 1000 > /sys/module/block/parameters/events_dfl_poll_msecs

After the command line above the memory card device were scanned and partition mounted automatically.
Note that the change will affect all block devices, not just the card reader, maybe not what you want.

Maybe there are better solutions, like adding some quirk to the kernel driver to enable polling for this device only, or use udev rules to enable polling only for this hardware when it is detected, leaving the global setting at it's default value.

Regression analysis:
Maybe in the past polling was enabled, I don't know if in the kernel or by some userspace component, and in newer versions it was disabled making the device look nonfunctional.

Ciao,
   Antonio http://ao2.it

P.S. To those complaining about old bugs not being fixed, if possible try providing the actual problematic hardware to developers, that generally gives them motivation to fix the problems.