openwrtv4/target/linux/brcm63xx/patches-4.9/001-4.11-01-mtd-m25p80-consider-max-message-size-in-m25p80_read.patch

From 80a79a889ce5df16c5261ab2f1e8e63b94b78102 Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Fri, 28 Oct 2016 07:58:46 +0200
Subject: [PATCH 1/8] mtd: m25p80: consider max message size in m25p80_read

Consider a message size limit when calculating the maximum amount
of data that can be read.

The message size limit has been introduced with 4.9, so cc it
to stable.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
---
 drivers/mtd/devices/m25p80.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -174,7 +174,8 @@ static ssize_t m25p80_read(struct spi_no
 
 	t[1].rx_buf = buf;
 	t[1].rx_nbits = m25p80_rx_nbits(nor);
-	t[1].len = min(len, spi_max_transfer_size(spi));
+	t[1].len = min3(len, spi_max_transfer_size(spi),
+			spi_max_message_size(spi) - t[0].len);
 	spi_message_add_tail(&t[1], &m);
 
 	ret = spi_sync(spi, &m);