> -----Original Message----- > From: Paul Walmsley [mailto:paul@xxxxxxxxx] > Sent: Monday, April 05, 2010 4:44 PM > To: Sripathy, Vishwanath > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: RE: [PATCHV3 1/2] OMAP3: Set MPU and IVA bypass Clock Divider > > On Mon, 5 Apr 2010, Sripathy, Vishwanath wrote: > > > > -----Original Message----- > > > From: Paul Walmsley [mailto:paul@xxxxxxxxx] > > > > > > On Thu, 1 Apr 2010, Vishwanath BS wrote: > > > > > > > diff --git a/arch/arm/mach-omap2/clock3xxx_data.c b/arch/arm/mach- > > > omap2/clock3xxx_data.c > > > > index d5153b6..d8e57a6 > > > > --- a/arch/arm/mach-omap2/clock3xxx_data.c > > > > +++ b/arch/arm/mach-omap2/clock3xxx_data.c > > > > @@ -3597,5 +3601,13 @@ int __init omap3xxx_clk_init(void) > > > > sdrc_ick_p = clk_get(NULL, "sdrc_ick"); > > > > arm_fck_p = clk_get(NULL, "arm_fck"); > > > > > > > > + /* Set the bypass clock dividers for DPLL1 and DPLL2 */ > > > > + if (cpu_is_omap3630()) { > > > > + clk_set_rate(&dpll1_fck, 400000000/2); > > > > + clk_set_rate(&dpll2_fck, 400000000/2); > > > > + } else { > > > > + clk_set_rate(&dpll1_fck, 332000000/4); > > > > + clk_set_rate(&dpll2_fck, 332000000/4); > > > > + } > > > > > > This code is highly OPP-specific. Why is this code needed here? > > > Shouldn't the code in resource34xx.c be sufficient? > > > > Code in resource34xx.c will be executed only when DVFS is executed. > > However above code makes sure that initial values of Bypass clock > > dividers are good. This will ensure that even if DVFS is disabled, > > IVA/MPU are never overclocked when they enter bypass mode. > > My point is that you don't know how the bootloader has configured the > system at the point when this code executes. You don't know what voltage > level VDD1 and VDD2 are at; you don't know what state the clock tree is > in. You only know this when you change OPPs. And the selection of the > OPP at startup is use-case dependent. > May be I can move this code to init_opp? > So as far as I can tell, this code shouldn't be there. If you want to do > something like this, then you should add some generic way (e.g., a kernel > command line parameter) to set the VDD1 and VDD2 OPPs at boot. > > > - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
