From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni) Date: Sun, 13 Apr 2014 16:39:41 +0200 Subject: [PATCH 04/29] memory: mvebu-devbus: fix the conversion of the bus width In-Reply-To: <1397400006-4315-1-git-send-email-thomas.petazzoni@free-electrons.com> References: <1397400006-4315-1-git-send-email-thomas.petazzoni@free-electrons.com> Message-ID: <1397400006-4315-5-git-send-email-thomas.petazzoni@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 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 Cc: stable at vger.kernel.org --- drivers/memory/mvebu-devbus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c index 110c036..b82cdf1 100644 --- a/drivers/memory/mvebu-devbus.c +++ b/drivers/memory/mvebu-devbus.c @@ -108,8 +108,12 @@ 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. + */ + r.bus_width = (r.bus_width / 8) - 1; err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps", &r.badr_skew); -- 1.8.3.2