José Roberto de Souza <jose.souza@xxxxxxxxx> writes: > When PSR/PSR2 is enabled hardware can do AUX transactions by it self, so > lets use the mutex register that is available in gen9+ to avoid concurrent > access by hardware and driver. > > Reference: https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-skl-vol12-display.pdf > Page 198 - AUX programming sequence > > As gen < 9 don't have the mutex PSR needs to be disabled, that is why the > 'else TODO' was added. This is also backed by spec: > "DDI A AUX channel transactions must not be sent while SRD is enabled. > SRD must be completely disabled before a DDI A AUX channel transaction can > be sent." BSpec: 7530 > > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_reg.h | 9 ++++++++ > drivers/gpu/drm/i915/intel_dp.c | 48 ++++++++++++++++++++++++++++++++++++++++ > drivers/gpu/drm/i915/intel_drv.h | 1 + > drivers/gpu/drm/i915/intel_psr.c | 6 +++++ > 4 files changed, 64 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h > index f6afa5e5e7c1..5d7736117cb9 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -5318,6 +5318,7 @@ enum { > #define _DPA_AUX_CH_DATA3 (dev_priv->info.display_mmio_offset + 0x6401c) > #define _DPA_AUX_CH_DATA4 (dev_priv->info.display_mmio_offset + 0x64020) > #define _DPA_AUX_CH_DATA5 (dev_priv->info.display_mmio_offset + 0x64024) > +#define _DPA_AUX_CH_MUTEX (dev_priv->info.display_mmio_offset + 0x6402C) > > #define _DPB_AUX_CH_CTL (dev_priv->info.display_mmio_offset + 0x64110) > #define _DPB_AUX_CH_DATA1 (dev_priv->info.display_mmio_offset + 0x64114) > @@ -5325,6 +5326,7 @@ enum { > #define _DPB_AUX_CH_DATA3 (dev_priv->info.display_mmio_offset + 0x6411c) > #define _DPB_AUX_CH_DATA4 (dev_priv->info.display_mmio_offset + 0x64120) > #define _DPB_AUX_CH_DATA5 (dev_priv->info.display_mmio_offset + 0x64124) > +#define _DPB_AUX_CH_MUTEX (dev_priv->info.display_mmio_offset + 0x6412C) > > #define _DPC_AUX_CH_CTL (dev_priv->info.display_mmio_offset + 0x64210) > #define _DPC_AUX_CH_DATA1 (dev_priv->info.display_mmio_offset + 0x64214) > @@ -5332,6 +5334,7 @@ enum { > #define _DPC_AUX_CH_DATA3 (dev_priv->info.display_mmio_offset + 0x6421c) > #define _DPC_AUX_CH_DATA4 (dev_priv->info.display_mmio_offset + 0x64220) > #define _DPC_AUX_CH_DATA5 (dev_priv->info.display_mmio_offset + 0x64224) > +#define _DPC_AUX_CH_MUTEX (dev_priv->info.display_mmio_offset + 0x6422C) > > #define _DPD_AUX_CH_CTL (dev_priv->info.display_mmio_offset + 0x64310) > #define _DPD_AUX_CH_DATA1 (dev_priv->info.display_mmio_offset + 0x64314) > @@ -5339,6 +5342,7 @@ enum { > #define _DPD_AUX_CH_DATA3 (dev_priv->info.display_mmio_offset + 0x6431c) > #define _DPD_AUX_CH_DATA4 (dev_priv->info.display_mmio_offset + 0x64320) > #define _DPD_AUX_CH_DATA5 (dev_priv->info.display_mmio_offset + 0x64324) > +#define _DPD_AUX_CH_MUTEX (dev_priv->info.display_mmio_offset + 0x6432C) > > #define _DPF_AUX_CH_CTL (dev_priv->info.display_mmio_offset + 0x64510) > #define _DPF_AUX_CH_DATA1 (dev_priv->info.display_mmio_offset + 0x64514) > @@ -5346,9 +5350,11 @@ enum { > #define _DPF_AUX_CH_DATA3 (dev_priv->info.display_mmio_offset + 0x6451c) > #define _DPF_AUX_CH_DATA4 (dev_priv->info.display_mmio_offset + 0x64520) > #define _DPF_AUX_CH_DATA5 (dev_priv->info.display_mmio_offset + 0x64524) > +#define _DPF_AUX_CH_MUTEX (dev_priv->info.display_mmio_offset + 0x6452C) > > #define DP_AUX_CH_CTL(port) _MMIO_PORT(port, _DPA_AUX_CH_CTL, _DPB_AUX_CH_CTL) > #define DP_AUX_CH_DATA(port, i) _MMIO(_PORT(port, _DPA_AUX_CH_DATA1, _DPB_AUX_CH_DATA1) + (i) * 4) /* 5 registers */ > +#define DP_AUX_CH_MUTEX(port) _MMIO_PORT(port, _DPA_AUX_CH_MUTEX, _DPB_AUX_CH_MUTEX) > > #define DP_AUX_CH_CTL_SEND_BUSY (1 << 31) > #define DP_AUX_CH_CTL_DONE (1 << 30) > @@ -5378,6 +5384,9 @@ enum { > #define DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(c) (((c) - 1) << 5) > #define DP_AUX_CH_CTL_SYNC_PULSE_SKL(c) ((c) - 1) > > +#define DP_AUX_CH_MUTEX_ENABLE (1 << 31) > +#define DP_AUX_CH_MUTEX_STATUS (1 << 30) > + > /* > * Computing GMCH M and N values for the Display Port link > * > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c > index f20b25f98e5a..bd5f1bb730ff 100644 > --- a/drivers/gpu/drm/i915/intel_dp.c > +++ b/drivers/gpu/drm/i915/intel_dp.c > @@ -1081,6 +1081,28 @@ static uint32_t intel_dp_get_aux_send_ctl(struct intel_dp *intel_dp, > aux_clock_divider); > } > > +static bool intel_dp_aux_get(struct drm_i915_private *dev_priv, > + struct intel_dp *intel_dp) > +{ > + int try, ret; Here you are not getting the aux. You are only getting checking if aux is available. My understanding of the spec is that the actual get is set Enable bit. > + > + for (try = 0, ret = -1; try < 3 && ret; try++) > + ret = wait_for(!(I915_READ_NOTRACE(intel_dp->aux_ch_mutex_reg) > + & DP_AUX_CH_MUTEX_STATUS), 0.5); what about intel_wait_for_register(dev_priv, intel_dp->aux_ch_mutex_reg, DP_AUX_CH_MUTEX_STATUS, 0, 500) ? > + > + return ret == 0; > +} > + > +static void intel_dp_aux_put(struct drm_i915_private *dev_priv, > + struct intel_dp *intel_dp) > +{ > + /* setting the status bit releases the mutex + keep set the bit > + * to keep the mutex enabled. > + */ > + I915_WRITE(intel_dp->aux_ch_mutex_reg, DP_AUX_CH_MUTEX_ENABLE | The enable bit is optional here. I believe it gets cleaner without it but with RMW. > + DP_AUX_CH_MUTEX_STATUS); > +} > + > static int > intel_dp_aux_ch(struct intel_dp *intel_dp, > const uint8_t *send, int send_bytes, > @@ -1115,6 +1137,21 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, > > intel_dp_check_edp(intel_dp); > > + /* Get hardware mutex when PSR is enabled */ > + if (dev_priv->psr.enabled == intel_dp) { > + if (intel_dp->aux_ch_mutex_reg.reg) { these checks could be inside get function. > + if (intel_dp_aux_get(dev_priv, intel_dp)) { > + DRM_WARN("dp_aux_ch port locked for too > long"); as well the message DRM_ERROR is enough I thing. > + ret = -EBUSY; also specific errno > + goto out_locked; > + } > + } else { > + /* TODO: go to PSR exit state waiting for change before > + * do a aux ch transaction. > + */ > + } > + } > + > /* Try to wait for any previous AUX channel activity */ > for (try = 0; try < 3; try++) { > status = I915_READ_NOTRACE(ch_ctl); > @@ -1243,7 +1280,16 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, > recv + i, recv_bytes - i); > > ret = recv_bytes; > + > out: > + if (dev_priv->psr.enabled == intel_dp) { we are checking psr.enable out of psr mutexes... probably better to only do this once on get part and if you got you put... > + if (intel_dp->aux_ch_mutex_reg.reg) > + intel_dp_aux_put(dev_priv, intel_dp); > + else > + /* TODO: schedule PSR work to active PSR again */ > + } > + > +out_locked: > pm_qos_update_request(&dev_priv->pm_qos, PM_QOS_DEFAULT_VALUE); > > if (vdd) > @@ -1496,6 +1542,8 @@ static void intel_aux_reg_init(struct intel_dp *intel_dp) > intel_dp->aux_ch_ctl_reg = intel_aux_ctl_reg(dev_priv, port); > for (i = 0; i < ARRAY_SIZE(intel_dp->aux_ch_data_reg); i++) > intel_dp->aux_ch_data_reg[i] = intel_aux_data_reg(dev_priv, port, i); > + if (INTEL_INFO(dev_priv)->gen >= 9) > + intel_dp->aux_ch_mutex_reg = DP_AUX_CH_MUTEX(port); > } > > static void > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index 898064e8bea7..0d235b7dab21 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -1040,6 +1040,7 @@ struct intel_dp { > i915_reg_t output_reg; > i915_reg_t aux_ch_ctl_reg; > i915_reg_t aux_ch_data_reg[5]; > + i915_reg_t aux_ch_mutex_reg; > uint32_t DP; > int link_rate; > uint8_t lane_count; > diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c > index 2ef374f936b9..8b456e4e1b47 100644 > --- a/drivers/gpu/drm/i915/intel_psr.c > +++ b/drivers/gpu/drm/i915/intel_psr.c > @@ -484,6 +484,9 @@ static void hsw_psr_enable_source(struct intel_dp *intel_dp, > EDP_PSR_DEBUG_MASK_HPD | > EDP_PSR_DEBUG_MASK_LPSP); > } > + > + if (intel_dp->aux_ch_mutex_reg.reg) > + I915_WRITE(intel_dp->aux_ch_mutex_reg, > DP_AUX_CH_MUTEX_ENABLE); My understanding is that set Enable is the actual get hw mutex, so I don't believe you want do do this here. Also you already check for psr.enable inside the aux transaction. setting there should be enough. > } > > /** > @@ -617,6 +620,9 @@ static void hsw_psr_disable(struct intel_dp *intel_dp, > else > WARN_ON(I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE); > } > + > + if (intel_dp->aux_ch_mutex_reg.reg) > + I915_WRITE(intel_dp->aux_ch_mutex_reg, ~DP_AUX_CH_MUTEX_ENABLE); > } > > /** > -- > 2.16.1 > > _______________________________________________ > 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
