From 1ea00d1a0323745093442b889e33e5e82924726a Mon Sep 17 00:00:00 2001
From: Björn Stenberg <bjorn@haxx.se>
Date: Tue, 3 Dec 2002 11:26:39 +0000
Subject: Added a >2ms delay in ata_hard_reset() before reading status, as per
 ATA specificatione (pedantic mode entered)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2902 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/drivers/ata.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

(limited to 'firmware/drivers/ata.c')

diff --git a/firmware/drivers/ata.c b/firmware/drivers/ata.c
index 0fbc418c2f..5cff8af19e 100644
--- a/firmware/drivers/ata.c
+++ b/firmware/drivers/ata.c
@@ -523,16 +523,20 @@ static void ata_thread(void)
     }
 }
 
+/* Hardware reset protocol as specified in chapter 9.1, ATA spec draft v5 */
 int ata_hard_reset(void)
 {
     int ret;
     
-    PADR &= ~0x0200;
+    /* state HRR0 */
+    PADR &= ~0x0200; /* assert _RESET */
+    sleep(1); /* > 25us */
 
-    sleep(2);
-
-    PADR |= 0x0200;
+    /* state HRR1 */
+    PADR |= 0x0200; /* negate _RESET */
+    sleep(1); /* > 2ms */
 
+    /* state HRR2 */
     ret = wait_for_bsy();
 
     /* Massage the return code so it is 0 on success and -1 on failure */
-- 
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