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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2014-04-14 17:29:18 +0200
committerJason Cooper <jason@lakedaemon.net>2014-04-17 06:14:30 +0200
commitce965c3d2e68c5325dd5624eb101d70423022fef (patch)
tree40600af7e250fbeeb5465a91e9142ffc5c62363f
parentLinux 3.15-rc1 (diff)
downloadlinux-ce965c3d2e68c5325dd5624eb101d70423022fef.tar.xz
linux-ce965c3d2e68c5325dd5624eb101d70423022fef.zip
memory: mvebu-devbus: fix the conversion of the bus width
According to the Armada 370 and Armada XP datasheets, the part of the Device Bus register that configure the bus width should contain 0 for a 8 bits bus width, and 1 for a 16 bits bus width (other values are unsupported/reserved). However, the current conversion done in the driver to convert from a bus width in bits to the value expected by the register leads to setting the register to 1 for a 8 bits bus, and 2 for a 16 bits bus. This mistake was compensated by a mistake in the existing Device Tree files for Armada 370/XP platforms: they were declaring a 8 bits bus width, while the hardware in fact uses a 16 bits bus width. This commit fixes that by adjusting the conversion logic. This patch fixes a bug that was introduced in 3edad321b1bd2e6c8b5f38146c115c8982438f06 ('drivers: memory: Introduce Marvell EBU Device Bus driver'), which was merged in v3.11. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1397489361-5833-2-git-send-email-thomas.petazzoni@free-electrons.com Fixes: 3edad321b1bd ('drivers: memory: Introduce Marvell EBU Device Bus driver') Cc: stable@vger.kernel.org # v3.11+ Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
-rw-r--r--drivers/memory/mvebu-devbus.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c
index 110c03627051..b59a17fb7c3e 100644
--- a/drivers/memory/mvebu-devbus.c
+++ b/drivers/memory/mvebu-devbus.c
@@ -108,8 +108,19 @@ static int devbus_set_timing_params(struct devbus *devbus,
node->full_name);
return err;
}
- /* Convert bit width to byte width */
- r.bus_width /= 8;
+
+ /*
+ * The bus width is encoded into the register as 0 for 8 bits,
+ * and 1 for 16 bits, so we do the necessary conversion here.
+ */
+ if (r.bus_width == 8)
+ r.bus_width = 0;
+ else if (r.bus_width == 16)
+ r.bus_width = 1;
+ else {
+ dev_err(devbus->dev, "invalid bus width %d\n", r.bus_width);
+ return -EINVAL;
+ }
err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
&r.badr_skew);