cmd640: fix deadlock on error handling

Stop abusing ide_lock lock (switch to a private locking).

Fixes same issue as fixed by Alan Cox in atiixp host driver with
commit 6c5f8cc33eb2e10b6ab788bbe259fc142a068627.

cmd640 is a bit special cause we still need to leave ide_lock for
->set_pio_mode with 'pio' argument == 8/9 (prefetch disable/enable).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 28 insertions, 20 deletions

diff --git a/drivers/ide/pci/cmd640.c b/drivers/ide/pci/cmd640.c
index f369645e4d16..0e9275d7459c 100644
--- a/drivers/ide/pci/cmd640.c
+++ b/drivers/ide/pci/cmd640.c
@@ -185,6 +185,8 @@ static u8 recovery_counts[4] = {16, 16, 16, 16}; /* Recovery count (encoded) */
 
 #endif /* CONFIG_BLK_DEV_CMD640_ENHANCED */
 
+static DEFINE_SPINLOCK(cmd640_lock);
+
 /*
  * These are initialized to point at the devices we control
  */
@@ -258,12 +260,12 @@ static u8 get_cmd640_reg_vlb (u16 reg)
 
 static u8 get_cmd640_reg(u16 reg)
 {
-        u8 b;
         unsigned long flags;
+        u8 b;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         b = __get_cmd640_reg(reg);
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
         return b;
 }
 
@@ -271,9 +273,9 @@ static void put_cmd640_reg(u16 reg, u8 val)
 {
         unsigned long flags;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         __put_cmd640_reg(reg,val);
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
 }
 
 static int __init match_pci_cmd640_device (void)
@@ -351,7 +353,7 @@ static int __init secondary_port_responding (void)
 {
         unsigned long flags;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
 
         outb_p(0x0a, 0x170 + IDE_SELECT_OFFSET);        /* select drive0 */
         udelay(100);
@@ -359,11 +361,11 @@ static int __init secondary_port_responding (void)
                 outb_p(0x1a, 0x170 + IDE_SELECT_OFFSET); /* select drive1 */
                 udelay(100);
                 if ((inb_p(0x170 + IDE_SELECT_OFFSET) & 0x1f) != 0x1a) {
-                        spin_unlock_irqrestore(&ide_lock, flags);
+                        spin_unlock_irqrestore(&cmd640_lock, flags);
                         return 0; /* nothing responded */
                 }
         }
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
         return 1; /* success */
 }
 
@@ -440,11 +442,11 @@ static void __init setup_device_ptrs (void)
 static void set_prefetch_mode (unsigned int index, int mode)
 {
         ide_drive_t *drive = cmd_drives[index];
+        unsigned long flags;
         int reg = prefetch_regs[index];
         u8 b;
-        unsigned long flags;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         b = __get_cmd640_reg(reg);
         if (mode) {     /* want prefetch on? */
 #if CMD640_PREFETCH_MASKS
@@ -460,7 +462,7 @@ static void set_prefetch_mode (unsigned int index, int mode)
                 b |= prefetch_masks[index];     /* disable prefetch */
         }
         __put_cmd640_reg(reg, b);
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
 }
 
 /*
@@ -561,7 +563,7 @@ static void program_drive_counts (unsigned int index)
         /*
          * Now that everything is ready, program the new timings
          */
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         /*
          * Program the address_setup clocks into ARTTIM reg,
          * and then the active/recovery counts into the DRWTIM reg
@@ -570,7 +572,7 @@ static void program_drive_counts (unsigned int index)
         setup_count |= __get_cmd640_reg(arttim_regs[index]) & 0x3f;
         __put_cmd640_reg(arttim_regs[index], setup_count);
         __put_cmd640_reg(drwtim_regs[index], pack_nibbles(active_count, recovery_count));
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
 }
 
 /*
@@ -630,6 +632,7 @@ static void cmd640_set_mode (unsigned int index, u8 pio_mode, unsigned int cycle
 
 static void cmd640_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
+        unsigned long flags;
         unsigned int index = 0, cycle_time;
         u8 b;
 
@@ -652,7 +655,12 @@ static void cmd640_set_pio_mode(ide_drive_t *drive, const u8 pio)
 
                 case 8: /* set prefetch off */
                 case 9: /* set prefetch on */
+                        /*
+                         * take ide_lock for drive->[no_]unmask/[no_]io_32bit
+                         */
+                        spin_lock_irqsave(&ide_lock, flags);
                         set_prefetch_mode(index, pio & 1);
+                        spin_unlock_irqrestore(&ide_lock, flags);
                         printk("%s: %sabled cmd640 prefetch\n", drive->name, (pio & 1) ? "en" : "dis");
                         return;
         }
@@ -670,20 +678,20 @@ static void cmd640_set_pio_mode(ide_drive_t *drive, const u8 pio)
 
 static int pci_conf1(void)
 {
-        u32 tmp;
         unsigned long flags;
+        u32 tmp;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         outb(0x01, 0xCFB);
         tmp = inl(0xCF8);
         outl(0x80000000, 0xCF8);
         if (inl(0xCF8) == 0x80000000) {
                 outl(tmp, 0xCF8);
-                spin_unlock_irqrestore(&ide_lock, flags);
+                spin_unlock_irqrestore(&cmd640_lock, flags);
                 return 1;
         }
         outl(tmp, 0xCF8);
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
         return 0;
 }
 
@@ -691,15 +699,15 @@ static int pci_conf2(void)
 {
         unsigned long flags;
 
-        spin_lock_irqsave(&ide_lock, flags);
+        spin_lock_irqsave(&cmd640_lock, flags);
         outb(0x00, 0xCFB);
         outb(0x00, 0xCF8);
         outb(0x00, 0xCFA);
         if (inb(0xCF8) == 0x00 && inb(0xCF8) == 0x00) {
-                spin_unlock_irqrestore(&ide_lock, flags);
+                spin_unlock_irqrestore(&cmd640_lock, flags);
                 return 1;
         }
-        spin_unlock_irqrestore(&ide_lock, flags);
+        spin_unlock_irqrestore(&cmd640_lock, flags);
         return 0;
 }