Re: TMSCSIM [2.6]

[Chiaki <ishikawa@yk.rim.or.jp>]

Chiaki wrote:
> Guennadi Liakhovetski wrote:
> 
>> Didn't pass uncompressed through - bigger than 100K? Attaching 
>> compressed.
>>
>> On Mon, 24 Nov 2003, Guennadi Liakhovetski wrote:
>>
>>
>>> Ghm, here's the patch. But I decided not to compress it, just send it as
>>> attachment, instead of inlining it - after all, this is how it should be
>>> done, isn't it?:-)
>>>
>>> And - now it includes one more fix - replaced deprecated check_region()
>>> with request_region() - noticed by Ishikawa, Chiaki.
> 
> 
> Hello,
> 
> Thank you for the renewed patch.
> 
> I am using TEKRAM dc390. I use tmscsim driver as a module.
> There is a PD/CD combo on the dc390 scsi bus. (PD is
> a somewhat outdated optomagnetic drive. The drive has
> two LUNs, one for CD, and one for PD. PD side is recognized as
> rewritable removable media at least under 2.4.22.)
> 
> With the modified tmscsim driver under 2.6.0-test10,
> (the bzipped patch submitted to linux-scsi worked without rejection)
> I got a panic after module insertion during booting.
> tmscsim is mentioned in /etc/modules and so inserted automatically
> during booting.
> 
> (More background: related stuff I can think of.
>       kernel 2.6.0-test10.
>       tmscsim ... used as module
>       sr ... module as sr_mod
>       event mechanism enabled in the kernel.
>       gcc 3.3 used...)

I should add that the PD/CD combo drive has only
one drive mechanism.
The drive detects the media and decides to
operate either as CD or PD drive at a time.
LUN 0 ... PD drive
LUN 1 ... CD drive
If I insert PD media, LUN 0 acts ad PD drive and
LUN 1 reports that CD is absent.
If I have CD media inside, then LUN 0 reports
that no writable media is inside and LUN 1 acts
as CD drive with media inside.
I have a CD media inside the combo drive and
so it is possible that the media detection might
play a role here (PD media is missing and
so the LUN0 reports no media inside.).


> 
> Here is the panic message left on the screen which I scribbed down
> manually.
> 
>     ... anything above is scrolled and disappeared but I saw the
>         module insertion began. ...
> esi: ef63a2f0 edi: 00000001 ebp: c03a5e4c esp: c03a5e3c
> ds: 007b es: 007b ss: 0068
> 
> Process swapper (pid:0, threadinfo = c03a4000, task=c0338680)
> 
> Stack: 00000000 ef63a2f0 efc617c0 ef5e92c0 c0ea5e8c f09451d1 ef63a2f0 
> ef63a2f0
>        ef5e92c0 ef5e92c0 c03a5ea4 f09451d1 ef63a2f0 4f89f21d 00000021 
> 00000001
>        cc000092 ef63a2f0 efc617c0 ef63a208 c03a5ec4 f0946e36 ef63a208 
> ef5e92c0
> 
> Call trace:
>   [<f09451d1>] dc390_StartSCCSI+0x41/0x330    [tmscsim]
>   [<f09451d1>] dc390_StartSCCSI+0x41/0x330    [tmscsim]
>   [<f0946e36>] dc390_SRBdone+0x306/0x5b0      [tmscsim]
>   [<f09472f3>] dc390_RequestSense+0x53/0x90   [tmscsim]
>   [<f0946714>] dc390_Disconnect+0x104/0x160    [tmscsim]
>   [<f094574a>] do_DC390_Interrupt:0x28d/0x350 [tmscsim]
>   [<c025dc88>] scsi_softirq+0xe8/0x240
>   [<c010da4b>] handle_IRQ_event:0x3b/0x70
>   [<c010e060>] do_IRQ+0x140/0x390
>   [<c0105000>] _stext+0x0/0xf0
>   [<c010c0ec>] common_interrupt:0x18/0x20
>   [<c0105000>] _stext+0x0/0xf0
>   [<c0108ea6>] default_idel+0x26/0x30
>   [<c0108f24>] cpu_idle+0x34/0x40
>   [<c03a6797>] start_kernel+0x1e7/0x270
>   [<c03a6480>] unknown_bootoption+0x0/0x100
> 
> Code: 0f 0b 28 00 77 9d 94 f0 eb c5 0f 0b 25 00 77 9d 94 f0 eb e8
> 
> <0> Kernel panic: Fatal exception in interrupt
>     In interrupt handler --- not syncing
> 
> 
> 
> 
> OBSERVATION:
> 
>     alt sysreq magic key combination worked.
>     I could run emergency sync and reboot.
> 
>     From the kernel panic message, and the call trace, it looks to
>     me that the interrupt is recursively entered somehow.
>     (Or unexpected interrupt came in.)
> 
> 
> So what next?
> I can enable debugging macro if necessary and re-try.
> 
> Or, I can disable tmscsim module insertion during booting,
> and try "insmod tmscsim" after the kernel is up and running and
> see if it makes difference.
> 
> (Under 2.6.0-test9, and manually fixed patched tmscsim files (due to
> whitespace problems of the patch), I could insert the tmscsim module
> but "insmod tmscsim" took unusually long time, but eventually
> returned. However, /proc/scsi/ didn't show the 2nd LUN of the
> PD/CD combo I have on dc390 bus. Maybe it was a problem of
> insertion of sr_mod due to my misconfiguration of module set up
> for 2.6.0-testXX which I believe is now corrected.
> Since immediately
> afterward when I tried automatic insertion of dc390 during booting,
> I got a similar panic which I reported above, I didn't pursue
> the insertion testing after the kernel is up and running.
> I thought fixing the panic of auto insertion needs to be handled first.
> But maybe I should re-try under test10 if this gives more insight.)
> 
> 
> 
> 


-- 
int main(void){int j=2003;/*(c)2003 cishikawa. */
char t[] ="<CI> @abcdefghijklmnopqrstuvwxyz.,\n\"";
char *i ="g>qtCIuqivb,gCwe\np@.ietCIuqi\"tqkvv is>dnamz";
while(*i)((j+=strchr(t,*i++)-(int)t),(j%=sizeof t-1),
(putchar(t[j])));return 0;}/* under GPL */