On Wed, May 15, 2013 at 10:07:35AM -0700, Tony Lindgren wrote: > * Mark A. Greer <mgreer@xxxxxxxxxxxxxxx> [130514 18:57]: > > On Tue, May 14, 2013 at 05:25:37PM -0700, Tony Lindgren wrote: > > > Commit a819c4f1 (ARM: OMAP3: PM: Only access IVA if one exists) > > > changed PM to not access IVA registers on omaps that don't have > > > them. Turns out we still need to idle iva2 as otherwise iva2_pwrdm > > > will stay on and block deeper idle states. > > > > > > Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> > > > > > > --- > > > > > > Paul & Kevin, do you have better ideas for fixing this? > > > > > > --- a/arch/arm/mach-omap2/pm34xx.c > > > +++ b/arch/arm/mach-omap2/pm34xx.c > > > @@ -546,8 +546,10 @@ static void __init prcm_setup_regs(void) > > > /* Clear any pending PRCM interrupts */ > > > omap2_prm_write_mod_reg(0, OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET); > > > > > > - if (omap3_has_iva()) > > > - omap3_iva_idle(); > > > + /* > > > + * We need to idle iva2_pwrdm even on am3703 with no iva2. > > > + */ > > > + omap3_iva_idle(); > > > > > > omap3_d2d_idle(); > > > } > > > > [Kevin, Paul, some background: Tony discovered that the am3703 needs > > to have omap3_iva_idle() called even though its not supposed to have > > an IVA.] > > > > This is potentially bad for other SoC's that don't have an IVA so I don't > > think its the way to go. My preference would be to set the OMAP3_HAS_IVA > > flag for the am3703 only since its the one with the bug. Maybe something > > in id.c:omap3xxx_check_features() but I don't see any existing way to check > > for an am3703 vs. other am37xx SoCs. Any ideas? > > > > Another option, I suppose, is a dts entry but I don't like that at all. > > It seems that iva2_pwrdm is there for all omap3 even if OMAP3_HAS_IVA > flag is unset. And if that's the case, iva2 clocks still need to be idled > in all cases. Ahh, this takes us to the "Great TI Docs Mystery" :) -- its basically impossible to tell because despite what their docs may say, the hardware can be quite different. I'm not sure how to proceed other than trial & error with as many different SoCs as we can find. > It's possible that not all steps in omap3_iva_idle() are needed though. > I can debug further to see which part of the omap3_iva_idle() are needed. > > Mark, do you have some omap3 with no iva (other than am3703) to test the > idle states with? I have an am35xx which isn't supposed to have an IVA so I can test with it (although, I'm not sure how well the kernel works on the am35xx these days). I'm a bit busy today but I'll try booting the am35xx tomorrow and if it comes up, see what I can figure out. Mark -- -- 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
