The complex main_running/queue_main mechanism is peculiar to
atari_NCR5380.c. It isn't SMP safe and offers little value given that
the work queue already offers concurrency management. Remove this
complexity to bring atari_NCR5380.c closer to NCR5380.c.
It is not a good idea to call the information transfer state machine from
queuecommand because, according to Documentation/scsi/scsi_mid_low_api.txt
that could happen in soft irq context. Fix this.
Signed-off-by: Finn Thain
---
drivers/scsi/NCR5380.h |1
drivers/scsi/atari_NCR5380.c | 80 +++
2 files changed, 6 insertions(+), 75 deletions(-)
Index: linux/drivers/scsi/NCR5380.h
===
--- linux.orig/drivers/scsi/NCR5380.h 2015-12-22 12:16:24.0 +1100
+++ linux/drivers/scsi/NCR5380.h2015-12-22 12:16:25.0 +1100
@@ -262,7 +262,6 @@ struct NCR5380_hostdata {
* transfer to handle chip overruns */
int retain_dma_intr;
struct work_struct main_task;
- volatile int main_running;
#ifdef SUPPORT_TAGS
struct tag_alloc TagAlloc[8][8];/* 8 targets and 8 LUNs */
#endif
Index: linux/drivers/scsi/atari_NCR5380.c
===
--- linux.orig/drivers/scsi/atari_NCR5380.c 2015-12-22 12:16:23.0
+1100
+++ linux/drivers/scsi/atari_NCR5380.c 2015-12-22 12:16:25.0 +1100
@@ -602,36 +602,6 @@ static void NCR5380_print_phase(struct S
#endif
-/*
- * ++roman: New scheme of calling NCR5380_main()
- *
- * If we're not in an interrupt, we can call our main directly, it cannot be
- * already running. Else, we queue it on a task queue, if not 'main_running'
- * tells us that a lower level is already executing it. This way,
- * 'main_running' needs not be protected in a special way.
- *
- * queue_main() is a utility function for putting our main onto the task
- * queue, if main_running is false. It should be called only from a
- * interrupt or bottom half.
- */
-
-#include
-#include
-#include
-
-static inline void queue_main(struct NCR5380_hostdata *hostdata)
-{
- if (!hostdata->main_running) {
- /* If in interrupt and NCR5380_main() not already running,
- queue it on the 'immediate' task queue, to be processed
- immediately after the current interrupt processing has
- finished. */
- queue_work(hostdata->work_q, &hostdata->main_task);
- }
- /* else: nothing to do: the running NCR5380_main() will pick up
- any newly queued command. */
-}
-
/**
* NCR58380_info - report driver and host information
* @instance: relevant scsi host instance
@@ -714,8 +684,6 @@ static void __maybe_unused NCR5380_print
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
local_irq_save(flags);
- printk("NCR5380: coroutine is%s running.\n",
- hostdata->main_running ? "" : "n't");
if (!hostdata->connected)
printk("scsi%d: no currently connected command\n", HOSTNO);
else
@@ -757,8 +725,6 @@ static int __maybe_unused NCR5380_show_i
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
local_irq_save(flags);
- seq_printf(m, "NCR5380: coroutine is%s running.\n",
- hostdata->main_running ? "" : "n't");
if (!hostdata->connected)
seq_printf(m, "scsi%d: no currently connected command\n",
HOSTNO);
else
@@ -997,17 +963,8 @@ static int NCR5380_queue_command(struct
dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n",
H_NO(cmd),
(cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
- /* If queue_command() is called from an interrupt (real one or bottom
-* half), we let queue_main() do the job of taking care about main. If
it
-* is already running, this is a no-op, else main will be queued.
-*
-* If we're not in an interrupt, we can call NCR5380_main()
-* unconditionally, because it cannot be already running.
-*/
- if (in_interrupt() || irqs_disabled())
- queue_main(hostdata);
- else
- NCR5380_main(&hostdata->main_task);
+ /* Kick off command processing */
+ queue_work(hostdata->work_q, &hostdata->main_task);
return 0;
}
@@ -1044,30 +1001,11 @@ static void NCR5380_main(struct work_str
unsigned long flags;
/*
-* We run (with interrupts disabled) until we're sure that none of
-* the host adapters have anything that can be done, at which point
-* we set main_running to 0 and exit.
-*
-* Interrupts are enabled before doing various other internal
-* instructions, after we've decided that we need to run through
-* the loop again.
-*
-*
