linux-kernel - [PATCH] x86, olpc: Wait for last byte of EC command to be accepted

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Message-Id: <20110726154226.93A9F9D401C@zog.reactivated.net>
Date:	Tue, 26 Jul 2011 16:42:26 +0100 (BST)
From:	Daniel Drake <dsd@...top.org>
To:	x86@...nel.org
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] x86, olpc: Wait for last byte of EC command to be accepted

From: Paul Fox <pgf@...top.org>

When executing EC commands, only waiting when there are still more bytes to
write is usually fine. However, if the system suspends very quickly after
a call to olpc_ec_cmd(), the last data byte may not yet be transferred to
the EC, and the command will not complete.

This solves a bug where the SCI wakeup mask was not correctly written
when going into suspend.

Signed-off-by: Paul Fox <pgf@...top.org>
Signed-off-by: Daniel Drake <dsd@...top.org>
---
 arch/x86/platform/olpc/olpc.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/olpc/olpc.c b/arch/x86/platform/olpc/olpc.c
index 8b9940e..7cce722 100644
--- a/arch/x86/platform/olpc/olpc.c
+++ b/arch/x86/platform/olpc/olpc.c
@@ -161,13 +161,13 @@ restart:
 	if (inbuf && inlen) {
 		/* write data to EC */
 		for (i = 0; i < inlen; i++) {
+			pr_devel("olpc-ec:  sending cmd arg 0x%x\n", inbuf[i]);
+			outb(inbuf[i], 0x68);
 			if (wait_on_ibf(0x6c, 0)) {
 				printk(KERN_ERR "olpc-ec:  timeout waiting for"
 						" EC accept data!\n");
 				goto err;
 			}
-			pr_devel("olpc-ec:  sending cmd arg 0x%x\n", inbuf[i]);
-			outb(inbuf[i], 0x68);
 		}
 	}
 	if (outbuf && outlen) {
-- 
1.7.6

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