/*
* Design
- * Issues :
*
- * The other Linux SCSI drivers were written when Linux was Intel PC-only,
- * and specifically for each board rather than each chip. This makes their
- * adaptation to platforms like the Mac (Some of which use NCR5380's)
- * more difficult than it has to be.
- *
- * Also, many of the SCSI drivers were written before the command queuing
- * routines were implemented, meaning their implementations of queued
- * commands were hacked on rather than designed in from the start.
- *
- * When I designed the Linux SCSI drivers I figured that
- * while having two different SCSI boards in a system might be useful
- * for debugging things, two of the same type wouldn't be used.
- * Well, I was wrong and a number of users have mailed me about running
- * multiple high-performance SCSI boards in a server.
- *
- * Finally, when I get questions from users, I have no idea what
- * revision of my driver they are running.
- *
- * This driver attempts to address these problems :
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* memory mapped) and drops this file in their 'C' wrapper.
*
+ * (Note from hch: unfortunately it was not enough for the different
+ * m68k folks and instead of improving this driver they copied it
+ * and hacked it up for their needs. As a consequence they lost
+ * most updates to this driver. Maybe someone will fix all these
+ * drivers to use a common core one day..)
+ *
* As far as command queueing, two queues are maintained for
* each 5380 in the system - commands that haven't been issued yet,
* and commands that are currently executing. This means that an
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
- * To solve the multiple-boards-in-the-same-system problem,
- * there is a separate instance structure for each instance
- * of a 5380 in the system. So, multiple NCR5380 drivers will
- * be able to coexist with appropriate changes to the high level
- * SCSI code.
- *
- * A NCR5380_PUBLIC_REVISION macro is provided, with the release
- * number (updated for each public release) printed by the
- * NCR5380_print_options command, which should be called from the
- * wrapper detect function, so that I know what release of the driver
- * users are using.
*
* Issues specific to the NCR5380 :
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
- * which is started when not running by the interrupt handler,
- * timer, and queue command function. It attempts to establish
- * I_T_L or I_T_L_Q nexuses by removing the commands from the
- * issue queue and calling NCR5380_select() if a nexus
- * is not established.
+ * which is started from a workqueue for each NCR5380 host in the
+ * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
+ * removing the commands from the issue queue and calling
+ * NCR5380_select() if a nexus is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
- * If nothing specific to this implementation needs doing (ie, with external
- * hardware), you must also define
- *
- * NCR5380_queue_command
- * NCR5380_reset
- * NCR5380_abort
- * NCR5380_proc_info
- *
- * to be the global entry points into the specific driver, ie
- * #define NCR5380_queue_command t128_queue_command.
- *
- * If this is not done, the routines will be defined as static functions
- * with the NCR5380* names and the user must provide a globally
- * accessible wrapper function.
- *
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID. If the
* driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
- * possible) function may be used. Before the specific driver initialization
- * code finishes, NCR5380_print_options should be called.
+ * possible) function may be used.
*/
+
static int do_abort(struct Scsi_Host *host);
static void do_reset(struct Scsi_Host *host);
git://git.onelab.eu / linux-2.6.git / blobdiff