On ke, 2016-03-23 at 04:43 +0000, Kannan, Vandana wrote: > > -----Original Message----- > > From: Ville Syrjälä [mailto:ville.syrjala@xxxxxxxxxxxxxxx] > > Sent: Monday, March 21, 2016 7:34 PM > > To: Kannan, Vandana <vandana.kannan@xxxxxxxxx> > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > Subject: Re: [PATCH] drm/i915: BXT DDI PHY sequence BUN > > > > On Mon, Mar 21, 2016 at 12:12:40PM +0530, Vandana Kannan wrote: > > > According to the BSpec update, bit 7 of PORT_CL1CM_DW0 register > > needs > > > to be checked to ensure that the register is in accessible state. > > > Also, based on a BSpec update, changing the timeout value to check > > > iphypwrgood, from 10ms to wait for up to 100us. > > > > > > Signed-off-by: Vandana Kannan <vandana.kannan@xxxxxxxxx> > > > Reported-by: Philippe Lecluse <Philippe.Lecluse@xxxxxxxxx> > > > Cc: Deak, Imre <imre.deak@xxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/i915_reg.h | 1 + > > > drivers/gpu/drm/i915/intel_ddi.c | 11 +++++++++-- > > > 2 files changed, 10 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h > > > b/drivers/gpu/drm/i915/i915_reg.h index 7dfc400..9a02bfc 100644 > > > --- a/drivers/gpu/drm/i915/i915_reg.h > > > +++ b/drivers/gpu/drm/i915/i915_reg.h > > > @@ -1318,6 +1318,7 @@ enum skl_disp_power_wells { > > > #define _PORT_CL1CM_DW0_A 0x162000 > > > #define _PORT_CL1CM_DW0_BC 0x6C000 > > > #define PHY_POWER_GOOD (1 << 16) > > > +#define PHY_RESERVED (1 << 7) > > > #define BXT_PORT_CL1CM_DW0(phy) _BXT_PHY((phy), > > _PORT_CL1CM_DW0_BC, \ > > > _PORT_CL1CM_DW0_A) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c > > > b/drivers/gpu/drm/i915/intel_ddi.c > > > index 62de9f4..354f949 100644 > > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > > @@ -2669,9 +2669,16 @@ static void broxton_phy_init(struct > > drm_i915_private *dev_priv, > > > val |= GT_DISPLAY_POWER_ON(phy); > > > I915_WRITE(BXT_P_CR_GT_DISP_PWRON, val); > > > > > > - /* Considering 10ms timeout until BSpec is updated */ > > > - if (wait_for(I915_READ(BXT_PORT_CL1CM_DW0(phy)) & > > PHY_POWER_GOOD, 10)) > > > + /* > > > + * HW team confirmed that the time to reach phypowergood status > > is > > > + * anywhere between 50 us and 100us. > > > + */ > > > + if (wait_for_atomic_us(((!(I915_READ(BXT_PORT_CL1CM_DW0(phy)) > > & > > > > Switching to atomic wait seems silly. > > > [Vandana] You think wait_for_us should suffice here? Yes. > > > + PHY_RESERVED)) && > > > + ((I915_READ(BXT_PORT_CL1CM_DW0(phy)) & > > > + PHY_POWER_GOOD) == > > PHY_POWER_GOOD)), 100)) { > > > DRM_ERROR("timeout during PHY%d power on\n", phy); > > > + } Please also add a comment on how the detection magic works: Reading any PHY register while the PHY is powered down will result in all register bits set, while the reserved bit 7 is guaranteed to be 0 when the PHY is powered up. --Imre > > > > > > for (port = (phy == DPIO_PHY0 ? PORT_B : PORT_A); > > > port <= (phy == DPIO_PHY0 ? PORT_C : PORT_A); port++) { > > > -- > > > 1.9.1 > > > > > > _______________________________________________ > > > Intel-gfx mailing list > > > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx > > > > -- > > Ville Syrjälä > > Intel OTC > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
