Gabor Juhos
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ca185b2a86
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clk: qcom: gcc-qcs404: fix initial rate of GPLL3
commit 36d202241d234fa4ac50743510d098ad52bd193a upstream.
The comment before the config of the GPLL3 PLL says that the
PLL should run at 930 MHz. In contrary to this, calculating
the frequency from the current configuration values by using
19.2 MHz as input frequency defined in 'qcs404.dtsi', it gives
921.6 MHz:
$ xo=19200000; l=48; alpha=0x0; alpha_hi=0x0
$ echo "$xo * ($((l)) + $(((alpha_hi << 32 | alpha) >> 8)) / 2^32)" | bc -l
921600000.00000000000000000000
Set 'alpha_hi' in the configuration to a value used in downstream
kernels [1][2] in order to get the correct output rate:
$ xo=19200000; l=48; alpha=0x0; alpha_hi=0x70
$ echo "$xo * ($((l)) + $(((alpha_hi << 32 | alpha) >> 8)) / 2^32)" | bc -l
930000000.00000000000000000000
The change is based on static code analysis, compile tested only.
[1] https://git.codelinaro.org/clo/la/kernel/msm-5.4/-/blob/kernel.lnx.5.4.r56-rel/drivers/clk/qcom/gcc-qcs404.c?ref_type=heads#L335
[2} https://git.codelinaro.org/clo/la/kernel/msm-5.15/-/blob/kernel.lnx.5.15.r49-rel/drivers/clk/qcom/gcc-qcs404.c?ref_type=heads#L127
Cc: stable@vger.kernel.org
Fixes: 652f1813c113 ("clk: qcom: gcc: Add global clock controller driver for QCS404")
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/r/20241022-fix-gcc-qcs404-gpll3-v1-1-c4d30d634d19@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2024-12-17 13:20:50 +01:00 |
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