[PATCH 3.13 098/103] i2c: mv64xxx: continue probe when clock-frequency is missing

Kamal Mostafa kamal at canonical.com
Tue Sep 30 21:31:43 UTC 2014 -stable review patch.  If anyone has any objections, please let me know.


From: Chen-Yu Tsai <wens at csie.org>

commit 0ce4bc1dbdd911ae1763e2d4ff36bd1b214a59f7 upstream.

The "clock-frequency" DT property is listed as optional, However,
the current code stores the return value of of_property_read_u32 in
the return code of mv64xxx_of_config, but then forgets to clear it
after setting the default value of "clock-frequency". It is then
passed out to the main probe function, resulting in a probe failure
when "clock-frequency" is missing.

This patch checks and then throws away the return value of
of_property_read_u32, instead of storing it and having to clear it

This issue was discovered after the property was removed from all
sunxi DTs.

Fixes: 4c730a06c19bb ("i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided")
Signed-off-by: Chen-Yu Tsai <wens at csie.org>
Acked-by: Andrew Lunn <andrew at lunn.ch>
Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
Signed-off-by: Wolfram Sang <wsa at the-dreams.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
 drivers/i2c/busses/i2c-mv64xxx.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index d52d849..cf89175 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -748,8 +748,7 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 	tclk = clk_get_rate(drv_data->clk);
-	rc = of_property_read_u32(np, "clock-frequency", &bus_freq);
-	if (rc)
+	if (of_property_read_u32(np, "clock-frequency", &bus_freq))
 		bus_freq = 100000; /* 100kHz by default */
 	if (!mv64xxx_find_baud_factors(bus_freq, tclk,

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