Messages in this thread | | | Date | Mon, 13 Feb 2006 21:28:17 +0100 | From | Stefan Richter <> | Subject | Re: [PATCH 7/8] don't mangle INQUIRY if cmddt or evpd bits are set |
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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.
> The latter > might be more interesting - RBC devices are only required to implement > MODE SENSE/SELECT page 6; they shouldn't get messed by the rest, but at > least some of them blindly respond with page 6 to _every_ MODE SENSE. > So that might be a good reason to blacklist.
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. 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). - 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.)
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. -- Stefan Richter -=====-=-==- --=- -==-= http://arcgraph.de/sr/ - 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/
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