On 09/07/2016 06:30 PM, Prabhakar Kushwaha wrote: > >> -----Original Message----- >> From: york sun >> Sent: Wednesday, September 07, 2016 9:17 PM >> To: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com>; u- >> b...@lists.denx.de >> Subject: Re: [PATCH] arch: ifc: update the IFC IP input clock >> >> On 09/06/2016 07:42 PM, Prabhakar Kushwaha wrote: >>> >>>> -----Original Message----- >>>> From: york sun >>>> Sent: Tuesday, September 06, 2016 9:10 PM >>>> To: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com>; u- >>>> b...@lists.denx.de >>>> Subject: Re: [PATCH] arch: ifc: update the IFC IP input clock >>>> >>>> On 09/06/2016 04:15 AM, Prabhakar Kushwaha wrote: >>>>> IFC IP clock is always a constant divisor of platform clock >>>>> pre-defined per SoC. Clock Control register (CCR) used in >>>>> current implementation governs IFC IP output clock. >>>>> >>>>> So update IFC IP clock to be defined as per predefined clock >>>>> divisor of platform clock. >>>>> >>>>> Signed-off-by: Prabhakar Kushwaha <prabhakar.kushw...@nxp.com> >>>>> --- >>>>> README | 3 +++ >>>>> arch/arm/cpu/armv7/ls102xa/clock.c | 10 ++-------- >>>>> arch/arm/cpu/armv8/fsl-layerscape/fsl_lsch2_speed.c | 10 ++-------- >>>>> arch/arm/cpu/armv8/fsl-layerscape/fsl_lsch3_speed.c | 10 ++-------- >>>>> arch/arm/include/asm/arch-fsl-layerscape/config.h | 3 +++ >>>>> arch/arm/include/asm/arch-ls102xa/config.h | 1 + >>>>> arch/powerpc/cpu/mpc85xx/speed.c | 10 ++-------- >>>>> arch/powerpc/include/asm/config_mpc85xx.h | 9 +++++++++ >>>>> 8 files changed, 24 insertions(+), 32 deletions(-) >>>> >>>> Prabkahar, >>>> >>>> Two concerns here >>>> >>>> 1, it is not only IFC for powerpc. Older SoCs have local bus. That's why >>>> the variable is named freq_localbus.. >>>> >>> >>> As per my understanding, Issue is valid for eLBC SoC also. >>> Just wanted to confirm from internal IP team before spinning patch to fix >>> it. >>> >>>> 2, what's the reason for this change? Is it wrong to use ccr to >>>> calculate the clock? Or is it because recent Layerscape SoCs have >>>> platform PLL different from platform clock? If the latter, can we limit >>>> the fix to platform clock and not changing powerpc? >>>> >>> >>> CCR governs the IFC output clock. >>> This clock is used for synchronous NOR, NAND flashes. It is nowhere govern >> IFC IP internal clock. >>> >>> It is true since conception of IFC. Unfortunately code written is wrong >>> since >> P1010. >>> It is confusing everyone. >>> >> >> Are you saying the freq_localbus should be the internal clock, not >> output clock? As far as I can remember, this variable has always be used >> for output clock since 85xx. I am open to the idea to change to internal >> clock only if it makes sense. Browsing the code, I see this variable is >> used for information only, except for setting arch.lbc_clk. >> > > Everyone believe it to be IFC internal clock not the output clock.
Not everyone. > As I always used to get query from customers about wrong IFC speed. > > So better to print IP clock to avoid any confusion. > IFC output clock will be printed when it is actually being used during > synchronous NOR, syn NAND. I am not against changing it to internal clock. But what are you going to print on the console? I think it is confusing to say IFC or local bus internal clock speed. Please also check how this clock is used and make sure arch.lbc_clk is still correct, after passing to Linux. York _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
