From 9144775590c99a54ee9fdda2e4ac2c835a52d5c6 Mon Sep 17 00:00:00 2001
From: Alan Cox <alan@redhat.com>
Date: Mon, 26 Jun 2006 00:26:12 -0700
Subject: [PATCH] --- yaml --- r: 30271 b: refs/heads/master c:
 4fb0f76d8cf4f7a3ffc36dd5e1bc8ca977b68824 h: refs/heads/master i:   30269:
 0bcf0f64690a3e7812ebbc551cdc36100346e5d0   30267:
 dd9edc8297591c159de23a477cf5cf938bcfc90f   30263:
 e179547dfa16841c30d4e039ac64bc9852d6d289   30255:
 0d8b704726047f4ce6323c491295ebee8223b275   30239:
 980766f129510d4268fca5eaab8cb6071094d439   30207:
 589ad079c10345de9d684b9e90fc5c2d801c6fff v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/ide/pci/piix.c | 12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 3d47cacdcc4e..304a369f3848 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b5cdccf841d7d29fb96e03de5a64ed395e0fde61
+refs/heads/master: 4fb0f76d8cf4f7a3ffc36dd5e1bc8ca977b68824
diff --git a/trunk/drivers/ide/pci/piix.c b/trunk/drivers/ide/pci/piix.c
index e9b83e1a3028..7fac6f57b5d6 100644
--- a/trunk/drivers/ide/pci/piix.c
+++ b/trunk/drivers/ide/pci/piix.c
@@ -222,6 +222,8 @@ static void piix_tune_drive (ide_drive_t *drive, u8 pio)
 	unsigned long flags;
 	u16 master_data;
 	u8 slave_data;
+	static DEFINE_SPINLOCK(tune_lock);
+
 				 /* ISP  RTC */
 	u8 timings[][2]	= { { 0, 0 },
 			    { 0, 0 },
@@ -230,7 +232,13 @@ static void piix_tune_drive (ide_drive_t *drive, u8 pio)
 			    { 2, 3 }, };
 
 	pio = ide_get_best_pio_mode(drive, pio, 5, NULL);
-	spin_lock_irqsave(&ide_lock, flags);
+
+	/*
+	 * Master vs slave is synchronized above us but the slave register is
+	 * shared by the two hwifs so the corner case of two slave timeouts in
+	 * parallel must be locked.
+	 */
+	spin_lock_irqsave(&tune_lock, flags);
 	pci_read_config_word(dev, master_port, &master_data);
 	if (is_slave) {
 		master_data = master_data | 0x4000;
@@ -250,7 +258,7 @@ static void piix_tune_drive (ide_drive_t *drive, u8 pio)
 	pci_write_config_word(dev, master_port, master_data);
 	if (is_slave)
 		pci_write_config_byte(dev, slave_port, slave_data);
-	spin_unlock_irqrestore(&ide_lock, flags);
+	spin_unlock_irqrestore(&tune_lock, flags);
 }
 
 /**