[PATCH 5.15 016/565] clk: qcom: gcc-qcs404: fix initial rate of GPLL3

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gabor Juhos <j4g8y7@xxxxxxxxx>

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@xxxxxxxxxxxxxxx
Fixes: 652f1813c113 ("clk: qcom: gcc: Add global clock controller driver for QCS404")
Signed-off-by: Gabor Juhos <j4g8y7@xxxxxxxxx>
Link: https://lore.kernel.org/r/20241022-fix-gcc-qcs404-gpll3-v1-1-c4d30d634d19@xxxxxxxxx
Signed-off-by: Bjorn Andersson <andersson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/clk/qcom/gcc-qcs404.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/clk/qcom/gcc-qcs404.c
+++ b/drivers/clk/qcom/gcc-qcs404.c
@@ -337,6 +337,7 @@ static struct clk_alpha_pll gpll1_out_ma
 /* 930MHz configuration */
 static const struct alpha_pll_config gpll3_config = {
 	.l = 48,
+	.alpha_hi = 0x70,
 	.alpha = 0x0,
 	.alpha_en_mask = BIT(24),
 	.post_div_mask = 0xf << 8,






[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux