From: Alan Cox <alan@linux.intel.com>
Date: Sat, 10 Oct 2015 20:48:52 +0000 (+0100)
Subject: devscsi: introduce a deselect
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=f249fbf978481c70c3eca82cc70c1298133475a7;p=FUZIX.git

devscsi: introduce a deselect

Needed for things like MPI or bank switched cartridges containing MMIO
controllers (MSX as well I suspect)
---

diff --git a/Kernel/dev/devscsi.c b/Kernel/dev/devscsi.c
index 0d394a62..11e59b6d 100644
--- a/Kernel/dev/devscsi.c
+++ b/Kernel/dev/devscsi.c
@@ -93,10 +93,11 @@ int si_docmd(uint8_t *data)
 			err = si_read(data);
 		else
 			err = si_write(data);
-		if (err)
-			return err;
 	}
-	return si_cmdend();
+	if (err == 0)
+		err = si_cmdend();
+	si_clear();		/* Clears any data on scsi bus */
+	si_deselect();
 }
 
 /*
@@ -135,8 +136,6 @@ uint8_t si_cmd(void)
 
 		if(!(err = si_docmd(blk_op.addr)))
 		  break;
-		si_clear();		/* Clears any data on scsi bus */
-		/*	si_restore(); Needed ?? - eg for SASI ? */
 	}
 
 	/* If any errors print error message */
@@ -145,6 +144,8 @@ uint8_t si_cmd(void)
 		/* If fatal error */
 		if(count == 10){
 			si_err("Fatal error\007 10 retries", err);
+                        /* Ugly - si_reset is odd and has to do its own
+                           select/deselect of the controller if needed */
 			si_reset();
 			return 0;
 		}
diff --git a/Kernel/dev/devscsi.h b/Kernel/dev/devscsi.h
index 728b1320..31b09032 100644
--- a/Kernel/dev/devscsi.h
+++ b/Kernel/dev/devscsi.h
@@ -157,5 +157,8 @@ extern uint8_t si_writecmd(uint8_t len);
 extern uint8_t si_select(void);
 /* Clear anything stuck on the bus, or wrong directions */
 extern void si_clear(void);
-/* Reset the bus if possible */
+/* Reset the bus if possible: Oddity - this one fn has to select the controller
+   itself then deselect (don't select a drive!) */
 extern void si_reset(void);
+/* Deselect the scsi controller */
+extern void si_deselect(void);
diff --git a/Kernel/dev/devscsi_discard.c b/Kernel/dev/devscsi_discard.c
index c71e8bce..ebb39cb9 100644
--- a/Kernel/dev/devscsi_discard.c
+++ b/Kernel/dev/devscsi_discard.c
@@ -33,10 +33,8 @@ void scsi_dev_init(uint8_t drive)
   si_dcb.device = drive;
   si_dcb.lun = 0;
   si_dcb.bus = 0;
-  kputchar('S');
   if (si_select())		/* Can't select it - probably not present */
     return;
-  kputchar('I');
   /* FIXME: check if this would be better as a memcpy of fixed struct */
   si_dcb.cb.cb0.opcode = SIINQUIRY;
   si_dcb.cb.cb0.hiblock = 0;
@@ -47,9 +45,11 @@ void scsi_dev_init(uint8_t drive)
   si_dcb.length = 36;
   si_dcb.direction = SIDIR_READ;
   si_user = 0;
+  
+  si_deselect();	/* As selects don't necessarily stack */
+  
   if (si_docmd(identify))
     return;
-  kputchar(':');
 
   p = identify + 8;
   while (p < identify + 27)