I have reworked (simplified) the patch that was discussed couple months back (http://marc.info/?l=linux-scsi&m=121900434020133&w=2). Again the goal is to ensure that host/target transfer parameters do not go out of sync (in the case the target is removed and added back either forcibly or by using remove/add-single-device through /proc/scsi/scsi): - sym_prepare_nego() now always fills a message which is either wide or ppr (the driver will do sync after wide when needed as before). - it is called when the host changes parameters, or if the command is INQUIRY or REQUEST SENSE (including check cond case). --- Change the sym53c8xx_2 driver negotiation logic so that the driver will tolerate better device removals. Negotiation message(s) will be sent with every INQUIRY and REQUEST SENSE command, and whenever there is a change in goals or when the device reports check condition. Signed-off-by: aaro.koskinen@xxxxxxx --- diff -uprN -X linux-2.6.27.5-orig/Documentation/dontdiff linux-2.6.27.5-orig/drivers/scsi/sym53c8xx_2/sym_hipd.c linux-2.6.27.5/drivers/scsi/sym53c8xx_2/sym_hipd.c --- linux-2.6.27.5-orig/drivers/scsi/sym53c8xx_2/sym_hipd.c 2008-11-07 19:55:34.000000000 +0200 +++ linux-2.6.27.5/drivers/scsi/sym53c8xx_2/sym_hipd.c 2008-11-19 12:15:05.000000000 +0200 @@ -1413,7 +1413,7 @@ static void sym_check_goals(struct sym_h } /* - * Prepare the next negotiation message if needed. + * Prepare the next negotiation message. * * Fill in the part of message buffer that contains the * negotiation and the nego_status field of the CCB. @@ -1433,24 +1433,14 @@ static int sym_prepare_nego(struct sym_h * Many devices implement PPR in a buggy way, so only use it if we * really want to. */ - if (goal->offset && - (goal->iu || goal->dt || goal->qas || (goal->period < 0xa))) { + if (goal->renego == NS_PPR || (goal->offset && + (goal->iu || goal->dt || goal->qas || (goal->period < 0xa)))) { nego = NS_PPR; - } else if (spi_width(starget) != goal->width) { - nego = NS_WIDE; - } else if (spi_period(starget) != goal->period || - spi_offset(starget) != goal->offset) { - nego = NS_SYNC; } else { - goal->check_nego = 0; - nego = 0; + nego = NS_WIDE; /* SYNC will follow WIDE if needed. */ } switch (nego) { - case NS_SYNC: - msglen += spi_populate_sync_msg(msgptr + msglen, goal->period, - goal->offset); - break; case NS_WIDE: msglen += spi_populate_width_msg(msgptr + msglen, goal->width); break; @@ -1469,7 +1459,6 @@ static int sym_prepare_nego(struct sym_h tp->nego_cp = cp; /* Keep track a nego will be performed */ if (DEBUG_FLAGS & DEBUG_NEGO) { sym_print_nego_msg(np, cp->target, - nego == NS_SYNC ? "sync msgout" : nego == NS_WIDE ? "wide msgout" : "ppr msgout", msgptr); } @@ -2049,11 +2038,9 @@ static void sym_setwide(struct sym_hcb * struct sym_tcb *tp = &np->target[target]; struct scsi_target *starget = tp->starget; - if (spi_width(starget) == wide) - return; - sym_settrans(np, target, 0, 0, 0, wide, 0, 0); + tp->tgoal.renego = NS_WIDE; tp->tgoal.width = wide; spi_offset(starget) = 0; spi_period(starget) = 0; @@ -2080,6 +2067,7 @@ sym_setsync(struct sym_hcb *np, int targ sym_settrans(np, target, 0, ofs, per, wide, div, fak); + tp->tgoal.renego = NS_WIDE; /* SYNC will follow WIDE. */ spi_period(starget) = per; spi_offset(starget) = ofs; spi_iu(starget) = spi_dt(starget) = spi_qas(starget) = 0; @@ -2106,6 +2094,7 @@ sym_setpprot(struct sym_hcb *np, int tar sym_settrans(np, target, opts, ofs, per, wide, div, fak); + tp->tgoal.renego = NS_PPR; spi_width(starget) = tp->tgoal.width = wide; spi_period(starget) = tp->tgoal.period = per; spi_offset(starget) = tp->tgoal.offset = ofs; @@ -5135,9 +5124,14 @@ int sym_queue_scsiio(struct sym_hcb *np, /* * Build a negotiation message if needed. * (nego_status is filled by sym_prepare_nego()) + * + * Always negotiate on INQUIRY and REQUEST SENSE. + * */ cp->nego_status = 0; - if (tp->tgoal.check_nego && !tp->nego_cp && lp) { + if ((tp->tgoal.check_nego || + cmd->cmnd[0] == INQUIRY || cmd->cmnd[0] == REQUEST_SENSE) && + !tp->nego_cp && lp) { msglen += sym_prepare_nego(np, cp, msgptr + msglen); } diff -uprN -X linux-2.6.27.5-orig/Documentation/dontdiff linux-2.6.27.5-orig/drivers/scsi/sym53c8xx_2/sym_hipd.h linux-2.6.27.5/drivers/scsi/sym53c8xx_2/sym_hipd.h --- linux-2.6.27.5-orig/drivers/scsi/sym53c8xx_2/sym_hipd.h 2008-11-07 19:55:34.000000000 +0200 +++ linux-2.6.27.5/drivers/scsi/sym53c8xx_2/sym_hipd.h 2008-11-19 12:14:46.000000000 +0200 @@ -354,6 +354,7 @@ struct sym_trans { unsigned int dt:1; unsigned int qas:1; unsigned int check_nego:1; + unsigned int renego:2; }; /* -- 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
