On Sat, Jun 24, 2006 at 04:30:46AM -0700, Andrew Morton wrote: [..] > > > > > > > > diff -puN drivers/block/cciss.c~cciss-initialization-issue-over-kdump-fix drivers/block/cciss.c > > > > --- linux-2.6.17-1M/drivers/block/cciss.c~cciss-initialization-issue-over-kdump-fix 2006-06-23 14:04:55.000000000 -0400 > > > > +++ linux-2.6.17-1M-vivek/drivers/block/cciss.c 2006-06-23 14:08:12.000000000 -0400 > > > > @@ -1976,6 +1976,13 @@ static int add_sendcmd_reject(__u8 cmd, > > > > ctlr, complete); > > > > /* not much we can do. */ > > > > #ifdef CONFIG_CISS_SCSI_TAPE > > > > + /* We might get notification of completion of commands > > > > + * which we never issued in this kernel if this boot is > > > > + * taking place after previous kernel's crash. Simply > > > > + * ignore the commands in this case. > > > > + */ > > > > + if (crash_boot) > > > > + return 0; > > > > return 1; > > > > > > Looks like this is working around a driver problem rather than fixing it > > > properly ;) > > > > That's true. Its more of a working around the problem. I think in all > > such cases we should soft reset the device so that device drops the messages > > issued from the context of previous kernel and starts afresh. > > Sounds good. > > > But looks like not all the devices provide software reset facility > > (Or I can't find it out from the source code or limited documentation > > available). Mike, can I soft reset this device? > > > > I am facing similar problem in megaraid driver as well where detailed > > technical documentation is not available and I can't find a way to > > soft reset the device. > > Megaraid has a maintainer who has documents and hardware engineers. > Well, maintainer mentioned that we do not export more documents more than what is available on LSI site. That site contains product specification, installation guides, user guides etc but not a technical document which gives insight into the various registers and what a driver writer can do with the device. I have also sent mails regarding my problem to linux-scsi list as well as to people working on megaraid but but no response. :-( > > Or is there a generic way to handle these situations? Fixing them driver > > by driver is a long painful process. > > Some generic way of whacking a PCI device via the standard PCI registers? > Not that I know of. Somebody hinted that think of PCI bus reset. But I think PCI bus reset will require firware/BIOS to export a hook to software to so initiate PCI bus reset and I don't think many platforms do that. Infact I am not even aware of one platform who does that. Thanks Vivek - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
