Arnd Bergmann wrote:
Am Donnerstag, 3. Januar 2002 22:42 schrieben Sie:
A rather old "CRW6416S" on a aic7xxx controller. It first did not work because I had an ISA SCSI card (aha1542) and AFAIR that does not work with scatter/gather the way that is needed by pktcdvd (more that 16 segments in one request).
Maybe this is my problem as well... No, you don't have an ISA card and it also does more that 16 segments per request (something like 128, I think).
Ah so. I thought the problem is on device side, not on the card side. Anyway, there are some problems with the latest aic7xxx driver, I have to boot twice after powerup, because the first start fails with "kerel panic: Loop 1" which is known and reported problem caused by some rewrite of the driver. But packet writing didn't work even with the older driver. The card and all the devices attached work well otherwise.
But it sucessfully writes some data before having problems. Well, that part actually _is_ the same with the aha1542 problem, just for a different reason.
I've done some more tests: dd-in exactly 16MB, either in 64kb ok 2kb blocks works perfectly (readback and cmp), but if I try something 64kb unaligned (I was testing dd-in of 260kb), the pktcdvd has problems prereading the rest of the last packet (it shedules reads and then ignores read errors although the medium is perfectly readable using any userland tool). It will then write the data as they are, so if I dd-out 260kb, I'll get written data but the rest of the last packet is empty (zeroes) instead of the original content. The rest of the disk is unchanged.
Is Jens/anybody else actively working on the driver now? (I've seen lots of Jens's work in 2.5.1 so I'm not sure if he still has time to work on pkt layer)
He once wrote that the work in 2.5.1 is required for packet writing to be cleanly implemented (the current approach is more of a hack), but I guess PW is still part of the big picture and will come when the rest has stabilized (a.k.a. not too soon).
So will the 2.5.x effort be ever backported to 2.4?
I think Peter Osterlund is more or less just porting pktcdvd along the kernels but not adding new features.
Then I'm on my own to hack it for my hardware :-)
Well, I'm not really following pktcdvd that closely anymore, so take this information with a grain of salt.
Arnd <><
Thanks for the info, Nenik