> Subject: Re: [PATCH v2] arm64: dts: imx8mp: Add DT nodes for the two ISPs > > On 6/11/24 3:04 AM, Peng Fan wrote: > >> Subject: Re: [PATCH v2] arm64: dts: imx8mp: Add DT nodes for the two > >> ISPs > >>>> > >>>>> Something like > >>>>> ---8<--- > >>>>> --- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi > >>>>> +++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi > >>>>> @@ -1837,11 +1837,13 @@ media_blk_ctrl: blk-ctrl@32ec0000 { > >>>>> <&clk IMX8MP_CLK_MEDIA_APB>, > >>>>> <&clk IMX8MP_CLK_MEDIA_DISP1_PIX>, > >>>>> <&clk > >>>>> IMX8MP_CLK_MEDIA_DISP2_PIX>, > >>>>> + <&clk > >>>>> + IMX8MP_CLK_MEDIA_ISP>, > >>>>> <&clk IMX8MP_VIDEO_PLL1>; > >>>>> assigned-clock-parents = <&clk > >> IMX8MP_SYS_PLL2_1000M>, > >>>>> <&clk IMX8MP_SYS_PLL1_800M>, > >>>>> <&clk IMX8MP_VIDEO_PLL1_OUT>, > >>>>> - <&clk IMX8MP_VIDEO_PLL1_OUT>; > >>>>> + <&clk IMX8MP_VIDEO_PLL1_OUT>, > >>>>> + <&clk > >>>>> + IMX8MP_SYS_PLL2_500M>; > >>>>> assigned-clock-rates = <500000000>, <200000000>, > >>>>> <0>, <0>, > >>>>> <1039500000>; > >>>> > >> > >> According to the i.MX8MP Data sheet, the nominal speed for > >> MEDIA_ISP_CLOCL_ROOT is 400MHZ with 500MHz being allowed in > overdrive > >> mode. > >> > >> I think this clock rate should drop to the nominal value of 400MHz > >> and those boards who support overdrive can increase it to 500MHz to > >> avoid stiability issues and/or running out of spec. I created an > >> imx8mm and imx8mn- overdrive.dtsi file. If there is interest, I can do the > same for the 8MP as well. > >> > >> I haven't gone through all the clocks to determine if/what clocks are > >> being overdriven. > > > > Shouldn't the bootloader take the work to runtime update the freq? > > Why need introduce an extra overdrive.dtsi? > > Shouldn't the overdrive/non-overdrive decision be done in board DT instead ? It is bootloader configure voltage to nominal, then bootloader should use nominal device tree or runtime update dtb. If bootloader configure voltage to over-drive, bootloader could use nominal or over-drive dtb If introduce x.dtsi and x-overdrive.dtsi, how to let board choose which dtsi to include? Regards, Peng.