X-Sender: ddkilzer@mail.earthlink.net In-Reply-To: <199809081041.LAA13960@lassi.cygnus.co.uk> X-Files: Sundays at 8 PM CDT on Fox! Date: Tue, 8 Sep 1998 07:53:35 -0500 To: Jesper Skov From: "David D. Kilzer" Subject: Re: L68K: NCR53C9x patch [forwarded message from Carsten Pluntke] Cc: linux-m68k@lists.linux-m68k.org X-MIME-Autoconverted: from quoted-printable to 8bit by www.phil.uni-sb.de id OAA27659 Sender: owner-linux-m68k@phil.uni-sb.de Here's the instant replay, sans MIME! This should help with many of the late Mac Quadras which use NCR53C96 chips (or NCR53C94 chips for the AV Macs). FWIW, Eudora did *NOT* decode this since the MIME content separators were 'destroyed' during the forwarding (%s/^-/- -/) and there were no MIME headers left in the forwarded message. Had to chop off everything but the encoded message part and run it through Mpack. Dave On 09/08/1998, Jesper Skov wrote: >------- start of forwarded message (RFC 934 encapsulation) ------- >From: Carsten Pluntke >To: Linux Kernel List >cc: Jesper Skov >Subject: [PATCH] NCR53C9x SCSI disconnect bugfix >Date: Tue, 8 Sep 1998 08:11:15 +0200 (MET DST) > >According to recent messages I fixed the bug in the NCR53C9x SCSI driver >which stops SCSI operation when a target disconnected. > >Another little bugfix concerns extremely slow targets (like my Microtek >ScanMaker 630) which doesn't free the bus quick enough to not to cause >confusion on fast systems. See comments in file. > > Carsten >[Attachment:NCR53C9x-patch] >------- end ------- diff -urN -X exclude linux-2.1.115/drivers/scsi/NCR53C9x.c linux-2.1.115-current/drivers/scsi/NCR53C9x.c --- linux-2.1.115/drivers/scsi/NCR53C9x.c Mon Sep 7 18:35:21 1998 +++ linux-2.1.115-current/drivers/scsi/NCR53C9x.c Mon Sep 7 19:21:05 1998 @@ -694,6 +694,7 @@ /* Initialize the command queues */ esp->current_SC = 0; esp->disconnected_SC = 0; + esp->disconnected_mask = 0; esp->issue_SC = 0; /* Clear the state machines. */ @@ -987,22 +988,41 @@ static inline void esp_exec_cmd(struct NCR_ESP *esp) { struct ESP_regs *eregs = esp->eregs; - Scsi_Cmnd *SCptr; + Scsi_Cmnd *SCptr, **SCptr2; Scsi_Device *SDptr; volatile unchar *cmdp = esp->esp_command; unsigned char the_esp_command; int lun, target; int i; - /* Hold off if we've been reselected or an IRQ is showing... */ - if(esp->disconnected_SC || esp->dma_irq_p(esp)) - return; + /* Hold off if an IRQ is showing... */ + if(esp->dma_irq_p(esp)) return; - /* Grab first member of the issue queue. */ - SCptr = esp->current_SC = remove_first_SC(&esp->issue_SC); + SCptr2 = &(esp->issue_SC); /* Safe to panic here because current_SC is null. */ - if(!SCptr) panic("esp: esp_exec_cmd and issue queue is NULL"); + if(!(*SCptr2)) panic("esp: esp_exec_cmd and issue queue is NULL"); + + /* Search for first command whose target is not disconnected + * (free bus means target is idle in that case) + */ + while(*SCptr2) + { + if(!(esp->disconnected_mask & (1 << ((*SCptr2)->target)))) break; + SCptr2 = (Scsi_Cmnd **) &((*SCptr2)->host_scribble); + } + + /* Here it means no suitable command found. */ + if(!(*SCptr2)) return; + + /* Grab member of the issue queue. */ + SCptr = esp->current_SC = remove_first_SC(SCptr2); + + /* + * Some devices (like my scanner) are so slow that we really need to + * make sure that the bus is free. + */ + while(esp->eregs->esp_status & ESP_STAT_PMASK); SDptr = SCptr->device; lun = SCptr->lun; @@ -2130,6 +2150,7 @@ esp_cmd(esp, eregs, ESP_CMD_ESEL); ESPDISC(("D<%02x,%02x>", SCptr->target, SCptr->lun)); append_SC(&esp->disconnected_SC, SCptr); + esp->disconnected_mask |= (1 << (SCptr->target)); esp->current_SC = NULL; if(esp->issue_SC) esp_exec_cmd(esp); @@ -2180,6 +2201,8 @@ esp_cmd(esp, eregs, ESP_CMD_NULL); } + esp->disconnected_mask &= ~(1 << target); + SCptr = remove_SC(&esp->disconnected_SC, (unchar) target, (unchar) lun); if(!SCptr) { Scsi_Cmnd *sp; diff -urN -X exclude linux-2.1.115/drivers/scsi/NCR53C9x.h linux-2.1.115-current/drivers/scsi/NCR53C9x.h --- linux-2.1.115/drivers/scsi/NCR53C9x.h Mon Aug 17 20:32:16 1998 +++ linux-2.1.115-current/drivers/scsi/NCR53C9x.h Mon Sep 7 18:45:26 1998 @@ -282,6 +282,11 @@ Scsi_Cmnd *current_SC; /* Who is currently working the bus */ Scsi_Cmnd *disconnected_SC; /* Commands disconnected from the bus */ + /* when fetching the next command out of issue_SC, ignore the targets + * whose bit is set; they're currently busy. + */ + int disconnected_mask; /* bit mask of disconnected targets */ + /* Message goo */ unchar cur_msgout[16]; unchar cur_msgin[16];