Messages in this thread | | | Date | Tue, 14 Feb 2006 02:40:49 +0000 | From | Al Viro <> | Subject | Re: [PATCH 7/8] don't mangle INQUIRY if cmddt or evpd bits are set |
| |
On Mon, Feb 13, 2006 at 09:28:17PM +0100, Stefan Richter wrote: > Al Viro wrote: > >On Mon, Feb 13, 2006 at 05:19:55PM +0100, Stefan Richter wrote: > >>BTW, a Prolific based enclosure indeed seems to be unable to handle > >>CD-ROMs after scsiinfo treatment. An enclosure based on an old > >>revision of TI StorageLynx apparently causes mode_sense -> check > >>condition/ unit attention loops when scsiinfo tries to access some > >>mode page. > > > >The former is best treated by using the hardware in question as a pissuary, > >to make sure that its contents matches the quality of design. > > I have got the impression that most of IEEE 1394a/ USB 2.0 combo bridges > on the market are now based on Prolific chips.
Unfortunately. Finding OXFW911-based ones for about the same price is still not hard...
> Some more findings: > - The TI StorageLynx based bridge reports device type 0 (TYPE_DISK). > The problem occurs apparently with page 4 and page 8. Sbp2 has a > fix since yesterday which sets the skip_ms_page_8 flag.
That's going to cause fun problems on reboot if it actually has write-behind cache...
> http://marc.theaimsgroup.com/?l=linux1394-devel&m=113969287630893 > - Another bridge made by the same manufacturer but based on TI > StorageLynx revision A features the same MODE SENSE bug. This bridge > reports type 14 (TYPE_RBC).
Pardon? If it's type 14, we won't issue MODE SENSE for page 8 and will go for page 6 instead...
> - I tested a tenth bridge now, based on Initio INIC-2430F. The bridge > reports TYPE_DISK and seems to support all pages which scsiinfo is > interested in. Sd_mod is a different story: After sd_mod accesses > page 8, the kernel panics. (This is discussed in another thread. The > mentioned sbp2 patch catches this bridge as a skip_ms_page_8 > candidate too, thus avoids the panic. I will eventually check what > sd_mod is doing; the sbp2 patch is not the real fix.)
sd_mod issues MODE SENSE from sd_read_cache_size() and does that twice - once for minimal length to get the length device wants to give and then for actual length.
> Of course sg does not care for any black list flags (like sd_mod and > sr_mod do), but considering the nature of the bugs and anticipated usage > of affected devices, there is hardly a reason for further safeguards in > sbp2, let alone sg.
Maybe, maybe not. Note that e.g. aforementioned INQUIRY bug in pl3507 is triggered by dmraid, which works via SG_IO, just as scsiinfo. And unlike scsiinfo it's run from /etc/rc.sysinit on current FC4... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |