This is a note to let you know that I've just added the patch titled
clk: axi-clkgen: Correctly handle nocount bit in recalc_rate()
to the 4.9-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: clk-axi-clkgen-correctly-handle-nocount-bit-in-recalc_rate.patch and it can be found in the queue-4.9 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 foo@baz Thu Mar 22 14:40:24 CET 2018
From: Lars-Peter Clausen lars@metafoo.de Date: Tue, 5 Sep 2017 11:32:40 +0200 Subject: clk: axi-clkgen: Correctly handle nocount bit in recalc_rate()
From: Lars-Peter Clausen lars@metafoo.de
[ Upstream commit 063578dc5f407f67d149133818efabe457daafda ]
If the nocount bit is set the divider is bypassed and the settings for the divider count should be ignored and a divider value of 1 should be assumed. Handle this correctly in the driver recalc_rate() callback.
While the driver sets up the part so that the read back dividers values yield the correct result the power-on reset settings of the part might not reflect this and hence calling e.g. clk_get_rate() without prior calls to clk_set_rate() will yield the wrong result.
Signed-off-by: Lars-Peter Clausen lars@metafoo.de Signed-off-by: Stephen Boyd sboyd@codeaurora.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/clk/clk-axi-clkgen.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-)
--- a/drivers/clk/clk-axi-clkgen.c +++ b/drivers/clk/clk-axi-clkgen.c @@ -40,6 +40,10 @@ #define MMCM_REG_FILTER1 0x4e #define MMCM_REG_FILTER2 0x4f
+#define MMCM_CLKOUT_NOCOUNT BIT(6) + +#define MMCM_CLK_DIV_NOCOUNT BIT(12) + struct axi_clkgen { void __iomem *base; struct clk_hw clk_hw; @@ -315,12 +319,27 @@ static unsigned long axi_clkgen_recalc_r unsigned int reg; unsigned long long tmp;
- axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); - dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_2, ®); + if (reg & MMCM_CLKOUT_NOCOUNT) { + dout = 1; + } else { + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLKOUT0_1, ®); + dout = (reg & 0x3f) + ((reg >> 6) & 0x3f); + } + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_DIV, ®); - d = (reg & 0x3f) + ((reg >> 6) & 0x3f); - axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); - m = (reg & 0x3f) + ((reg >> 6) & 0x3f); + if (reg & MMCM_CLK_DIV_NOCOUNT) + d = 1; + else + d = (reg & 0x3f) + ((reg >> 6) & 0x3f); + + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB2, ®); + if (reg & MMCM_CLKOUT_NOCOUNT) { + m = 1; + } else { + axi_clkgen_mmcm_read(axi_clkgen, MMCM_REG_CLK_FB1, ®); + m = (reg & 0x3f) + ((reg >> 6) & 0x3f); + }
if (d == 0 || dout == 0) return 0;
Patches currently in stable-queue which might be from lars@metafoo.de are
queue-4.9/clk-axi-clkgen-correctly-handle-nocount-bit-in-recalc_rate.patch