This fix handles the case where an application requests that an odd number of bytes of data be transferred either from or to a wide (16 bit) device (usually a tape drive) on an LSI Logic adapter controlled by the sym53c8xx_2 driver. Our customer has provided us with an application that allows a user to specify how many bytes of data to write or read from the wide tape drive. Baring an NDA agreement, I probably could provide the application if necessary. -----Original Message----- From: Tony Battersby [mailto:tonyb@xxxxxxxxxxxxxxx] Sent: Tuesday, June 14, 2005 3:01 PM To: 'Matthew Wilcox'; 'Stephens, Larry' Cc: 'Linux-Scsi@Vger. Kernel. Org (E-mail)' Subject: RE: Sym53c8xx_2 Odd Byte Data Transfer patches > While this patch does seem to solve the problem of transferring an odd > number of bytes to the device, I recently received a bug report saying > that we don't accept an odd number of bytes transferred from a device. > It seems to me that it's going to require modifying the scsi > scripts in > order to do this. Do you agree? Have you looked into > transfers in the > opposite direction as part of this work? If a target sends an odd number of bytes during a wide DATA IN phase, then it should send an IGNORE WIDE RESIDUE message immediately after exiting the data phase to inform the initiator. The sym53c8xx_2 driver in the 2.4 kernel series handles this correctly except on a REQUEST SENSE command issued for autosense (previously sym53c8xx_2 would reject an IWR message for autosense; I submitted a patch a good while ago to make it ignore IWR in this case instead of rejecting it). Not accounting for IWR on autosense is not a big deal though, so I consider sym53c8xx_2 in 2.4 kernels to handle odd-length DATA IN phases acceptably. I haven't tested the 2.6 kernels. Anthony J. Battersby Cybernetics - : 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
