m68k: amiflop - Get rid of sleep_on calls

Apart from sleep_on() calls that could be easily converted to
wait_event() and completion calls amiflop also used a flag in ms_delay()
and ms_isr() as a custom mutex for ms_delay() without a need for
explicit unlocking.  I converted that to a standard mutex.

The replacement for the unconditional sleep_on() in fd_motor_on() is a
complete_all() together with a INIT_COMPLETION() before the mod_timer()
call.  It appears to me that fd_motor_on() might be called concurrently
and fd_select() does not guarantee mutual exclusivity in the case the
same drive gets selected again.

Signed-off-by: Andreas Bombe <aeb@debian.org>
Acked-by: Jörg Dorchain <joerg@dorchain.net>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 16 insertions, 24 deletions

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 4b1d4ac960f1..8df436ff7068 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -156,7 +156,7 @@ static volatile int fdc_busy = -1;
 static volatile int fdc_nested;
 static DECLARE_WAIT_QUEUE_HEAD(fdc_wait);
  
-static DECLARE_WAIT_QUEUE_HEAD(motor_wait);
+static DECLARE_COMPLETION(motor_on_completion);
 
 static volatile int selected = -1;      /* currently selected drive */
 
@@ -184,8 +184,7 @@ static unsigned char mfmencode[16]={
 static unsigned char mfmdecode[128];
 
 /* floppy internal millisecond timer stuff */
-static volatile int ms_busy = -1;
-static DECLARE_WAIT_QUEUE_HEAD(ms_wait);
+static DECLARE_COMPLETION(ms_wait_completion);
 #define MS_TICKS ((amiga_eclock+50)/1000)
 
 /*
@@ -211,8 +210,7 @@ static int fd_device[4] = { 0, 0, 0, 0 };
 
 static irqreturn_t ms_isr(int irq, void *dummy)
 {
-        ms_busy = -1;
-        wake_up(&ms_wait);
+        complete(&ms_wait_completion);
         return IRQ_HANDLED;
 }
 
@@ -220,19 +218,17 @@ static irqreturn_t ms_isr(int irq, void *dummy)
    A more generic routine would do a schedule a la timer.device */
 static void ms_delay(int ms)
 {
-        unsigned long flags;
         int ticks;
+        static DEFINE_MUTEX(mutex);
+
         if (ms > 0) {
-                local_irq_save(flags);
-                while (ms_busy == 0)
-                        sleep_on(&ms_wait);
-                ms_busy = 0;
-                local_irq_restore(flags);
+                mutex_lock(&mutex);
                 ticks = MS_TICKS*ms-1;
                 ciaa.tblo=ticks%256;
                 ciaa.tbhi=ticks/256;
                 ciaa.crb=0x19; /*count eclock, force load, one-shoot, start */
-                sleep_on(&ms_wait);
+                wait_for_completion(&ms_wait_completion);
+                mutex_unlock(&mutex);
         }
 }
 
@@ -254,8 +250,7 @@ static void get_fdc(int drive)
         printk("get_fdc: drive %d  fdc_busy %d  fdc_nested %d\n",drive,fdc_busy,fdc_nested);
 #endif
         local_irq_save(flags);
-        while (!try_fdc(drive))
-                sleep_on(&fdc_wait);
+        wait_event(fdc_wait, try_fdc(drive));
         fdc_busy = drive;
         fdc_nested++;
         local_irq_restore(flags);
@@ -330,7 +325,7 @@ static void fd_deselect (int drive)
 static void motor_on_callback(unsigned long nr)
 {
         if (!(ciaa.pra & DSKRDY) || --on_attempts == 0) {
-                wake_up (&motor_wait);
+                complete_all(&motor_on_completion);
         } else {
                 motor_on_timer.expires = jiffies + HZ/10;
                 add_timer(&motor_on_timer);
@@ -347,11 +342,12 @@ static int fd_motor_on(int nr)
                 unit[nr].motor = 1;
                 fd_select(nr);
 
+                INIT_COMPLETION(motor_on_completion);
                 motor_on_timer.data = nr;
                 mod_timer(&motor_on_timer, jiffies + HZ/2);
 
                 on_attempts = 10;
-                sleep_on (&motor_wait);
+                wait_for_completion(&motor_on_completion);
                 fd_deselect(nr);
         }
 
@@ -582,8 +578,7 @@ static void raw_read(int drive)
 {
         drive&=3;
         get_fdc(drive);
-        while (block_flag)
-                sleep_on(&wait_fd_block);
+        wait_event(wait_fd_block, !block_flag);
         fd_select(drive);
         /* setup adkcon bits correctly */
         custom.adkcon = ADK_MSBSYNC;
@@ -598,8 +593,7 @@ static void raw_read(int drive)
 
         block_flag = 1;
 
-        while (block_flag)
-                sleep_on (&wait_fd_block);
+        wait_event(wait_fd_block, !block_flag);
 
         custom.dsklen = 0;
         fd_deselect(drive);
@@ -616,8 +610,7 @@ static int raw_write(int drive)
                 rel_fdc();
                 return 0;
         }
-        while (block_flag)
-                sleep_on(&wait_fd_block);
+        wait_event(wait_fd_block, !block_flag);
         fd_select(drive);
         /* clear adkcon bits */
         custom.adkcon = ADK_PRECOMP1|ADK_PRECOMP0|ADK_WORDSYNC|ADK_MSBSYNC;
@@ -1294,8 +1287,7 @@ static int non_int_flush_track (unsigned long nr)
                         writepending = 0;
                         return 0;
                 }
-                while (block_flag == 2)
-                        sleep_on (&wait_fd_block);
+                wait_event(wait_fd_block, block_flag != 2);
         }
         else {
                 local_irq_restore(flags);