Hi Michael, 2014-04-11 3:47 GMT+02:00 Michael Schmitz <schmitzmic@xxxxxxxxx>: > The more important issue is the one about the one-byte reconnect > message. Does the manual speak to that particular issue? Any hint on > how we could enable SCSI-2 features on chip init? There's the SCSI2 bit in the Config 2 register and/or the QTE bit in the Config 3 register. The 53CF9x-2 manual says about SCSI-2 bit: Bit 2 SCSI-2 Setting this bit allows the FSC to support two new features adopted in SCSI-2: the 3-byte message exchange for Tagged-Queueing and Group 2 commands. These features can also be set independently in the Config 3 register. Tagged-Queueing When this bit is set and the FSC is selected with ATN (Attention), it will request either one or three message bytes depending on whether ATN remains true or goes false. If ATN is still true after the first byte has been received, the FSC may request two more message bytes before switching to Command phase. If ATN goes false, it will switch to Command phase after the first message byte. When the bit is not set it will request a single message byte (as a target) when selected with ATN, and abort the selection sequence (as an initiator) if the target does not switch to Command phase after one message byte has been transferred. Group 2 Commands (seems to only be relevant for target mode). And about the QTE bit: Bit 6 Queue Tag Enable When this bit is set, the 53CF94/96 can receive 3-byte messages during bus-initiated Select With ATN. This feature is also enabled by setting bit 3 in the Configuration 2 register. The message bytes consist of a one-byte identify message and a two-byte queue tag message. The middle byte is the tagged queue message itself and the last byte is the tag value (0 to 255). When this bit is set, the second byte is checked to see if it is a valid queue tagging message. If the value of the byte is not 20, 21 or 22h, the sequence halts and an interrupt is generated. When this bit is not set, the chip aborts the Select With ATN sequence after it receives one Identify Message byte, if ATN is still asserted. Then there is a section called "Bus Initiated Reselection": Bus Initiated Reselection The FSC will allow itself to be reselected as an initiator by a target if it has previously received the Enable Selection/Reselection command. If the sequence completes normally, the following information will be in the FIFO: * Bus ID * Identify Message * Optional 2-byte queue tag message The bus ID will always be present and will always be one byte. It is an un-encoded version of the state of the bus during Reselection phase. The identify message will always be present and will always be one byte. If queue tagging is enabled, and the target is sending a queue tag message, the target will also send two queue tag message bytes. > Can you point me to a source for the manuals if possible? I only have dead tree versions of the QLogic manual and the Symbios Logic manual. The only public place I know of is bitsavers, they do have a manual for the 53C94/95/96 online here: http://bitsavers.trailing-edge.com/pdf/ncr/scsi/NCR_53C94_53C95_53C96_Data_Sheet_Feb90.pdf. I put the 53C90A/B manual online at http://members.home.nl/karsdejong/NCR53C90ab.pdf and a preliminary version of the 53CF94/96-2 at http://members.home.nl/karsdejong/NCR53CF9x-2.pdf. Kind regards, Kars. -- To unsubscribe from this list: 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
