This is a note to let you know that I've just added the patch titled

rtc: m41t80: fix m41t80_sqw_round_rate return value

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: rtc-m41t80-fix-m41t80_sqw_round_rate-return-value.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From c8384bb04261b9d32fe7402a6068ddaf38913b23 Mon Sep 17 00:00:00 2001

From: Troy Kisky troy.kisky@boundarydevices.com Date: Thu, 2 Nov 2017 18:58:13 -0700 Subject: rtc: m41t80: fix m41t80_sqw_round_rate return value

From: Troy Kisky troy.kisky@boundarydevices.com

commit c8384bb04261b9d32fe7402a6068ddaf38913b23 upstream.

Previously it was returning the best of 32768, 8192, 1024, 64, 2, 0

Now, best of 32768, 8192, 4096, 2048, 1024, 512, 256, 128, 64, 32, 16, 8, 4, 2, 1, 0

Signed-off-by: Troy Kisky troy.kisky@boundarydevices.com Signed-off-by: Alexandre Belloni alexandre.belloni@free-electrons.com Cc: Christoph Fritz chf.fritz@googlemail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/rtc/rtc-m41t80.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-)

--- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -468,18 +468,13 @@ static unsigned long m41t80_sqw_recalc_r static long m41t80_sqw_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { - int i, freq = M41T80_SQW_MAX_FREQ; - - if (freq <= rate) - return freq; - - for (i = 2; i <= ilog2(M41T80_SQW_MAX_FREQ); i++) { - freq /= 1 << i; - if (freq <= rate) - return freq; - } - - return 0; + if (rate >= M41T80_SQW_MAX_FREQ) + return M41T80_SQW_MAX_FREQ; + if (rate >= M41T80_SQW_MAX_FREQ / 4) + return M41T80_SQW_MAX_FREQ / 4; + if (!rate) + return 0; + return 1 << ilog2(rate); }

static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate,

Patches currently in stable-queue which might be from troy.kisky@boundarydevices.com are

queue-4.14/rtc-m41t80-m41t80_sqw_set_rate-should-return-0-on-success.patch queue-4.14/rtc-m41t80-avoid-i2c-read-in-m41t80_sqw_is_prepared.patch queue-4.14/rtc-m41t80-avoid-i2c-read-in-m41t80_sqw_recalc_rate.patch queue-4.14/rtc-m41t80-remove-unneeded-checks-from-m41t80_sqw_set_rate.patch queue-4.14/rtc-m41t80-fix-m41t80_sqw_round_rate-return-value.patch