From a9948b6194b46e489aa3b4d111d6dfd786c39c4b Mon Sep 17 00:00:00 2001
From: David Brownell <david-b@pacbell.net>
Date: Sun, 2 Apr 2006 10:37:40 -0800
Subject: [PATCH] SPI: spi bounce buffer has a minimum length

Make sure that spi_write_then_read() can always handle at least 32 bytes
of transfer (total, both directions), minimizing one portability issue.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/spi/spi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 94f5e8ed83a7..1168ef015887 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -522,7 +522,8 @@ int spi_sync(struct spi_device *spi, struct spi_message *message)
 }
 EXPORT_SYMBOL_GPL(spi_sync);
 
-#define	SPI_BUFSIZ	(SMP_CACHE_BYTES)
+/* portable code must never pass more than 32 bytes */
+#define	SPI_BUFSIZ	max(32,SMP_CACHE_BYTES)
 
 static u8	*buf;
 
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