A gap beyond a frame duration for disabling the layer in overlay manager and go bit setting on the corresponding video port may lead to SYNC_LOST. Fix by moving the layer to the non-visible area and deferring the ENABLE=0 write, immediately before the GO bit, guaranteeing both occur within the same frame window.
Link: https://www.ti.com/lit/pdf/sprz530 Signed-off-by: Yashas D <[email protected]> --- drivers/gpu/drm/tidss/tidss_dispc.c | 108 ++++++++++++++++++++++++++++ drivers/gpu/drm/tidss/tidss_dispc.h | 1 + 2 files changed, 109 insertions(+) diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c index 58d5eb033bdb..6cbf9dfc38b8 100644 --- a/drivers/gpu/drm/tidss/tidss_dispc.c +++ b/drivers/gpu/drm/tidss/tidss_dispc.c @@ -38,6 +38,8 @@ #include "tidss_dispc_regs.h" #include "tidss_scale_coefs.h" +#define OVR_LAYER_MAX_POS(mask) FIELD_MAX(mask) + static const u16 tidss_k2g_common_regs[DISPC_COMMON_REG_TABLE_LEN] = { [DSS_REVISION_OFF] = 0x00, [DSS_SYSCONFIG_OFF] = 0x04, @@ -467,6 +469,8 @@ struct dispc_device { struct clk *fclk; + unsigned long fclk_rate; + bool is_enabled; struct dss_vp_data vp_data[TIDSS_MAX_PORTS]; @@ -477,6 +481,9 @@ struct dispc_device { u32 memory_bandwidth_limit; struct dispc_errata errata; + + // WA for erratum i2097: OVR Layer Disable May Cause Sync Lost. + u32 pending_disable_layers[TIDSS_MAX_PORTS]; }; static void dispc_write(struct dispc_device *dispc, u16 reg, u32 val) @@ -1128,6 +1135,12 @@ static void dispc_enable_am65x_oldi(struct dispc_device *dispc, u32 hw_videoport void dispc_vp_prepare(struct dispc_device *dispc, u32 hw_videoport, const struct drm_crtc_state *state) { + /* + * WA for erratum i2097: clear any stale layer disable tracking + * state left over from the previous VP enable/disable cycle. + */ + dispc->pending_disable_layers[hw_videoport] = 0; + const struct tidss_crtc_state *tstate = to_tidss_crtc_state(state); const struct dispc_bus_format *fmt; const struct drm_display_mode *mode = &state->adjusted_mode; @@ -1233,6 +1246,38 @@ void dispc_vp_go(struct dispc_device *dispc, u32 hw_videoport) { WARN_ON(VP_REG_GET(dispc, hw_videoport, DISPC_VP_CONTROL, DISPC_VP_CONTROL_GOBIT_MASK)); + + if (dispc->errata.i2097 && + dispc->pending_disable_layers[hw_videoport]) { + u32 layer; + u32 delay_ns; + + /* WA for erratum i2097: set GO bit #1 to latch position + * changes into the DSS pipeline, wait 10 DSS functional clock + * cycles, then write ENABLE=0. + */ + VP_REG_FLD_MOD(dispc, hw_videoport, DISPC_VP_CONTROL, 1, + DISPC_VP_CONTROL_GOBIT_MASK); + + if (dispc->fclk_rate) + delay_ns = DIV_ROUND_UP_ULL((u64)10 * NSEC_PER_SEC, + dispc->fclk_rate); + else + delay_ns = 500; + + ndelay(delay_ns); + + for (layer = 0; layer < dispc->feat->num_vids; layer++) { + if (dispc->pending_disable_layers[hw_videoport] & + BIT(layer)) + OVR_REG_FLD_MOD(dispc, hw_videoport, + DISPC_OVR_ATTRIBUTES(layer), + 0, + DISPC_OVR_ATTRIBUTES_ENABLE_MASK); + } + dispc->pending_disable_layers[hw_videoport] = 0; + } + VP_REG_FLD_MOD(dispc, hw_videoport, DISPC_VP_CONTROL, 1, DISPC_VP_CONTROL_GOBIT_MASK); } @@ -1503,6 +1548,63 @@ void dispc_ovr_enable_layer(struct dispc_device *dispc, if (dispc->feat->subrev == DISPC_K2G) return; + if (dispc->errata.i2097 && !enable) { + /* + * WA for erratum i2097: + * + * Do not write ENABLE=0 directly. Instead move the layer to + * the non-visible area so it contributes no pixels. + * + * Position register layout differs per SoC: + * J721E : DISPC_OVR_ATTRIBUTES2, X[13:0], Y[29:16] (14-bit) + * Others: DISPC_OVR_ATTRIBUTES, X[17:6], Y[30:19] (12-bit) + */ + switch (dispc->feat->subrev) { + case DISPC_J721E: + OVR_REG_FLD_MOD(dispc, hw_videoport, + DISPC_OVR_ATTRIBUTES2(layer), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES2_POSX_MASK), + DISPC_OVR_ATTRIBUTES2_POSX_MASK); + OVR_REG_FLD_MOD(dispc, hw_videoport, + DISPC_OVR_ATTRIBUTES2(layer), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES2_POSY_MASK), + DISPC_OVR_ATTRIBUTES2_POSY_MASK); + break; + case DISPC_AM62L: + OVR_REG_FLD_MOD(dispc, 0, + DISPC_OVR_ATTRIBUTES(0), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES_POSX_MASK), + DISPC_OVR_ATTRIBUTES_POSX_MASK); + OVR_REG_FLD_MOD(dispc, 0, + DISPC_OVR_ATTRIBUTES(0), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES_POSY_MASK), + DISPC_OVR_ATTRIBUTES_POSY_MASK); + break; + default: + OVR_REG_FLD_MOD(dispc, hw_videoport, + DISPC_OVR_ATTRIBUTES(layer), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES_POSX_MASK), + DISPC_OVR_ATTRIBUTES_POSX_MASK); + OVR_REG_FLD_MOD(dispc, hw_videoport, + DISPC_OVR_ATTRIBUTES(layer), + OVR_LAYER_MAX_POS(DISPC_OVR_ATTRIBUTES_POSY_MASK), + DISPC_OVR_ATTRIBUTES_POSY_MASK); + break; + } + + dispc->pending_disable_layers[hw_videoport] |= BIT(layer); + return; + } + + if (dispc->errata.i2097 && enable) { + /* + * Layer being re-enabled: cancel any pending disable so + * dispc_vp_go() does not write ENABLE=0 after we have + * just written ENABLE=1 here. + */ + dispc->pending_disable_layers[hw_videoport] &= ~BIT(layer); + } + OVR_REG_FLD_MOD(dispc, hw_videoport, DISPC_OVR_ATTRIBUTES(layer), !!enable, DISPC_OVR_ATTRIBUTES_ENABLE_MASK); } @@ -2871,6 +2973,12 @@ static void dispc_init_errata(struct dispc_device *dispc) dispc->errata.i2000 = true; dev_info(dispc->dev, "WA for erratum i2000: YUV formats disabled\n"); } + + if (dispc->feat->subrev != DISPC_K2G) { + dispc->errata.i2097 = true; + dev_info(dispc->dev, + "WA for erratum i2097: OVR layer disable uses non-visible area\n"); + } } /* diff --git a/drivers/gpu/drm/tidss/tidss_dispc.h b/drivers/gpu/drm/tidss/tidss_dispc.h index 739d211d0018..e2ce9fdf1279 100644 --- a/drivers/gpu/drm/tidss/tidss_dispc.h +++ b/drivers/gpu/drm/tidss/tidss_dispc.h @@ -57,6 +57,7 @@ struct dispc_vid_info { struct dispc_errata { bool i2000; /* DSS Does Not Support YUV Pixel Data Formats */ + bool i2097; /* OVR Layer Disable May Cause Sync Lost */ }; enum dispc_vp_bus_type { -- 2.34.1
