Re: [linux-usb-devel] 2.6.19-rc1-mm1 - locks when using "dd bs=1M"from card reader

From: Helge Hafting
Date: Tue Oct 24 2006 - 06:20:46 EST


Christopher "Monty" Montgomery wrote:
On 10/20/06, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
At this point it's beyond me. Monty will have to take it from here.

I will look more closely at what might have changed there. Despite
the code refactoring (and a hand-resolved patch collision at that
point) the async disable handling *should* have been functionally
unchanged from 2.6.18. I will revisit that closely.

Has it actually been demonstrated that this does not crash 2.6.18
(pre-my-patches) kernels?
I just tested this. 2.6.18 does not crash. I still get tons of errors,
and no data. Copying using 1MB chunks or 4kB chunks
don't matter, it doesn't work. So card, reader or driver must be faulty.
The card works in a windows machine though.

2.6.19-rc1 gets data with 4kB chunks, and BUGs with 1M chunks.
If it crashes earlier, that doesn't mean
I'm uninterested in fixing it, I just want to know. I don't think
that had been explicitly answered earlier in the thread.
2.6.18 wasn't tried before, the reason being I did not have this
card reader when 2.6.18 was current.

dmesg output for 2.6.18 (after the dd attempts) is attached. I have
edited out stuff that isn't usb or scsi.

Helge Hafting

Attachment: dmesg3.gz
Description: application/gzip