On Fri, Jun 15, 2018 at 08:58:28PM +0300, Ville Syrjälä wrote:
> On Wed, May 23, 2018 at 11:04:35AM -0700, Lucas De Marchi wrote:
> > This became dead code with commit 309bd8ed464f ("drm/i915: Reinstate
> > GMBUS and AUX interrupts on gen4/g4x").
> >
> > v2: Move comment about HW behavior to where decision is made to enable
> > MSI (Ville).
> >
> > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> > Signed-off-by: Lucas De Marchi <lucas.demar...@intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_drv.c | 6 ++++++
> > drivers/gpu/drm/i915/i915_drv.h | 10 ----------
> > drivers/gpu/drm/i915/intel_dp.c | 22 +++++++---------------
> > drivers/gpu/drm/i915/intel_drv.h | 1 -
> > drivers/gpu/drm/i915/intel_psr.c | 2 +-
> > 5 files changed, 14 insertions(+), 27 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c
> > b/drivers/gpu/drm/i915/i915_drv.c
> > index 9c449b8d8eab..a1461de20472 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -1189,6 +1189,12 @@ static int i915_driver_init_hw(struct
> > drm_i915_private *dev_priv)
> > * get lost on g4x as well, and interrupt delivery seems to stay
> > * properly dead afterwards. So we'll just disable them for all
> > * pre-gen5 chipsets.
> > + *
> > + * dp aux and gmbus irq on gen4 seems to be able to generate legacy
> > + * interrupts even when in MSI mode. This results in spurious
> > + * interrupt warnings if the legacy irq no. is shared with another
> > + * device. The kernel then disables that interrupt source and so
> > + * prevents the other device from working properly.
> > */
> > if (INTEL_GEN(dev_priv) >= 5) {
> > if (pci_enable_msi(pdev) < 0)
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h
> > b/drivers/gpu/drm/i915/i915_drv.h
> > index b86ed6401120..c5e1f648c47c 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -2558,16 +2558,6 @@ intel_info(const struct drm_i915_private *dev_priv)
> > (IS_CANNONLAKE(dev_priv) || \
> > IS_SKL_GT3(dev_priv) || IS_SKL_GT4(dev_priv))
> >
> > -/*
> > - * dp aux and gmbus irq on gen4 seems to be able to generate legacy
> > interrupts
> > - * even when in MSI mode. This results in spurious interrupt warnings if
> > the
> > - * legacy irq no. is shared with another device. The kernel then disables
> > that
> > - * interrupt source and so prevents the other device from working properly.
> > - *
> > - * Since we don't enable MSI anymore on gen4, we can always use GMBUS/AUX
> > - * interrupts.
> > - */
> > -#define HAS_AUX_IRQ(dev_priv) true
> > #define HAS_GMBUS_IRQ(dev_priv) (INTEL_GEN(dev_priv) >= 4)
> >
> > /* With the 945 and later, Y tiling got adjusted so that it was 32 128-byte
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c
> > b/drivers/gpu/drm/i915/intel_dp.c
> > index ce07bd794aed..1dab40056df7 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -936,7 +936,7 @@ intel_dp_check_edp(struct intel_dp *intel_dp)
> > }
> >
> > static uint32_t
> > -intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
> > +intel_dp_aux_wait_done(struct intel_dp *intel_dp)
> > {
> > struct drm_i915_private *dev_priv = to_i915(intel_dp_to_dev(intel_dp));
> > i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
> > @@ -944,14 +944,10 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp,
> > bool has_aux_irq)
> > bool done;
> >
> > #define C (((status = I915_READ_NOTRACE(ch_ctl)) &
> > DP_AUX_CH_CTL_SEND_BUSY) == 0)
> > - if (has_aux_irq)
> > - done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
> > - msecs_to_jiffies_timeout(10));
> > - else
> > - done = wait_for(C, 10) == 0;
> > + done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
> > + msecs_to_jiffies_timeout(10));
> > if (!done)
> > - DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
> > - has_aux_irq);
> > + DRM_ERROR("dp aux hw did not signal timeout!\n");
> > #undef C
> >
> > return status;
> > @@ -1016,7 +1012,6 @@ static uint32_t skl_get_aux_clock_divider(struct
> > intel_dp *intel_dp, int index)
> > }
> >
> > static uint32_t g4x_get_aux_send_ctl(struct intel_dp *intel_dp,
> > - bool has_aux_irq,
> > int send_bytes,
> > uint32_t aux_clock_divider)
> > {
> > @@ -1037,7 +1032,7 @@ static uint32_t g4x_get_aux_send_ctl(struct intel_dp
> > *intel_dp,
> >
> > return DP_AUX_CH_CTL_SEND_BUSY |
> > DP_AUX_CH_CTL_DONE |
> > - (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) |
> > + DP_AUX_CH_CTL_INTERRUPT |
> > DP_AUX_CH_CTL_TIME_OUT_ERROR |
> > timeout |
> > DP_AUX_CH_CTL_RECEIVE_ERROR |
> > @@ -1047,13 +1042,12 @@ static uint32_t g4x_get_aux_send_ctl(struct
> > intel_dp *intel_dp,
> > }
> >
> > static uint32_t skl_get_aux_send_ctl(struct intel_dp *intel_dp,
> > - bool has_aux_irq,
> > int send_bytes,
> > uint32_t unused)
> > {
> > return DP_AUX_CH_CTL_SEND_BUSY |
> > DP_AUX_CH_CTL_DONE |
> > - (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) |
> > + DP_AUX_CH_CTL_INTERRUPT |
> > DP_AUX_CH_CTL_TIME_OUT_ERROR |
> > DP_AUX_CH_CTL_TIME_OUT_MAX |
> > DP_AUX_CH_CTL_RECEIVE_ERROR |
> > @@ -1076,7 +1070,6 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> > int i, ret, recv_bytes;
> > uint32_t status;
> > int try, clock = 0;
> > - bool has_aux_irq = HAS_AUX_IRQ(dev_priv);
> > bool vdd;
> >
> > ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
> > @@ -1131,7 +1124,6 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> >
> > while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp,
> > clock++))) {
> > u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
> > - has_aux_irq,
> > send_bytes,
> > aux_clock_divider);
> >
> > @@ -1148,7 +1140,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> > /* Send the command and wait for it to complete */
> > I915_WRITE(ch_ctl, send_ctl);
> >
> > - status = intel_dp_aux_wait_done(intel_dp, has_aux_irq);
> > + status = intel_dp_aux_wait_done(intel_dp);
> >
> > /* Clear done status and any errors */
> > I915_WRITE(ch_ctl,
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index 2855363f5b6c..7ac91d5ee3fa 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1138,7 +1138,6 @@ struct intel_dp {
> > * register with to kick off an AUX transaction.
> > */
> > uint32_t (*get_aux_send_ctl)(struct intel_dp *dp,
> > - bool has_aux_irq,
> > int send_bytes,
> > uint32_t aux_clock_divider);
> >
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index db27f2faa1de..ee26f5f33b87 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -373,7 +373,7 @@ static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
> > aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);
> >
> > /* Start with bits set for DDI_AUX_CTL register */
> > - aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, 0, sizeof(aux_msg),
> > + aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, sizeof(aux_msg),
> > aux_clock_divider);
>
> Hmm. What's the situation with the PSR stuff here?
I hadn't notice this, thanks.
I don't see why it would actually be correct though. It seems to be a
bug since d4dcbdceabe4 ("drm/i915/psr: Use ->get_aux_send_ctl
functions") when the rmw was removed (so whatever was on the register
before get overwritten).
CC'ing Daniel who wrote that patch and José/DK who worked recently on
psr stuff.
Lucas De Marchi
>
> >
> > /* Select only valid bits for SRD_AUX_CTL */
> > --
> > 2.17.0
>
> --
> Ville Syrjälä
> Intel
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