| Message ID | 20241022-fix-gcc-qcs404-gpll3-v1-1-c4d30d634d19@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | clk: qcom: gcc-qcs404: fix initial rate of GPLL3 | expand |
Hi Bryan, 2024. 10. 22. 11:53 keltezéssel, Bryan O'Donoghue írta: > On 22/10/2024 10:45, Gabor Juhos wrote: >> 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> > It should be possible to test / verify this change with debugcc on qcs404 > > https://github.com/linux-msm/debugcc/blob/master/qcs404.c Thank you for the suggestion. Unfortunately, I have no suitable hardware to test that. -Gabor
On Tue, 22 Oct 2024 11:45:56 +0200, Gabor Juhos wrote: > 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 > > [...] Applied, thanks! [1/1] clk: qcom: gcc-qcs404: fix initial rate of GPLL3 commit: 36d202241d234fa4ac50743510d098ad52bd193a Best regards,
diff --git a/drivers/clk/qcom/gcc-qcs404.c b/drivers/clk/qcom/gcc-qcs404.c index c3cfd572e7c1e0a987519be2cb2050c9bc7992c7..5ca003c9bfba89bee2e626b3c35936452cc02765 100644 --- a/drivers/clk/qcom/gcc-qcs404.c +++ b/drivers/clk/qcom/gcc-qcs404.c @@ -131,6 +131,7 @@ static struct clk_alpha_pll gpll1_out_main = { /* 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,
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> --- Note: due to a bug in the clk_alpha_pll_configure() function, the following patch is also needed in order for this fix to take effect: https://lore.kernel.org/all/20241019-qcs615-mm-clockcontroller-v1-1-4cfb96d779ae@quicinc.com/ --- drivers/clk/qcom/gcc-qcs404.c | 1 + 1 file changed, 1 insertion(+) --- base-commit: 03dc72319cee7d0dfefee9ae7041b67732f6b8cd change-id: 20241021-fix-gcc-qcs404-gpll3-f314335c8ecf Best regards,