Re: Zip 100 ATAPI not working, "qc timeout" and "failed to clear UNIT ATTENTION"

[Niklas Cassel <cassel@kernel.org>]

On Fri, Feb 21, 2025 at 05:08:21PM +0000, Philip Pemberton wrote:
> On 21/02/2025 01:57, Niklas Cassel wrote:
> > Please try this patch:
> > https://lore.kernel.org/linux-ide/20250221015422.20687-2-cassel@kernel.org/T/#u
> > 
> > and see if it fixes your problem.
> > 
> > Please also make sure to check that you can still write and read back what
> > you wrote to the device (with the read data matching the written data).
> 
> I can confirm the patch works!

Thanks for testing, and thanks for actually taking the time to debug this!


> Dump the original contents of the disk:
> # ddrescue /dev/sdb zip_orig
> GNU ddrescue 1.27
> Press Ctrl-C to interrupt
>      ipos:  100597 kB, non-trimmed:        0 B,  current rate:    589 kB/s
>      opos:  100597 kB, non-scraped:        0 B,  average rate:    792 kB/s
> non-tried:        0 B,  bad-sector:        0 B,    error rate:       0 B/s
>   rescued:  100663 kB,   bad areas:        0,        run time:      2m  6s
> pct rescued:  100.00%, read errors:        0,  remaining time:         n/a
>                               time since last successful read:         n/a
> Copying non-tried blocks... Pass 1 (forwards)
> Finished
> 
> Create 100MB of randomness, write it to the disk:
> # dd if=/dev/urandom of=ziptest bs=512 count=196608
> 196608+0 records in
> 196608+0 records out
> 100663296 bytes (101 MB, 96 MiB) copied, 2.74086 s, 36.7 MB/s
> # dd if=ziptest of=/dev/sdb bs=512
> 196608+0 records in
> 196608+0 records out
> 100663296 bytes (101 MB, 96 MiB) copied, 226.022 s, 445 kB/s
> 
> Read it back:
> # ddrescue /dev/sdb ziptest_read
> GNU ddrescue 1.27
> Press Ctrl-C to interrupt
>      ipos:  100597 kB, non-trimmed:        0 B,  current rate:    196 kB/s
>      opos:  100597 kB, non-scraped:        0 B,  average rate:   1059 kB/s
> non-tried:        0 B,  bad-sector:        0 B,    error rate:       0 B/s
>   rescued:  100663 kB,   bad areas:        0,        run time:      1m 34s
> pct rescued:  100.00%, read errors:        0,  remaining time:         n/a
>                               time since last successful read:         n/a
> Copying non-tried blocks... Pass 1 (forwards)
> Finished
> 
> Compare:
> # md5sum ziptest*
> f132f7ad38beef40d45ce9f96a6e9f92  ziptest
> f132f7ad38beef40d45ce9f96a6e9f92  ziptest_read

Certainly good enough for me, I will add your Tested-by tag!

Considering that this has been broken for 19 years, a few more weeks
will be quick in comparison. I will queue it for 6.15 just to get some
extra testing.


Kind regards,
Niklas