> -----Original Message----- > From: Lee, Shawn C <[email protected]> > Sent: Thursday, August 12, 2021 9:13 PM > To: [email protected] > Cc: Nikula, Jani <[email protected]>; [email protected]; > Kulkarni, Vandita <[email protected]>; Chiou, Cooper > <[email protected]>; Tseng, William <[email protected]>; Lee, > Shawn C <[email protected]>; Jani Nikula <[email protected]> > Subject: [v4 3/7] drm/i915/dsi: wait for header and payload credit available > > Driver should wait for free header or payload buffer in FIFO. > It would be good to wait a while for HW to release credit before give it up to > write to HW. Without sending initailize command sets completely. It would > caused MIPI display can't light up properly. > > Cc: Ville Syrjala <[email protected]> > Cc: Jani Nikula <[email protected]> > Cc: Vandita Kulkarni <[email protected]> > Cc: Cooper Chiou <[email protected]> > Cc: William Tseng <[email protected]> > Signed-off-by: Lee Shawn C <[email protected]>
Looks good to me. Reviewed-by: Vandita Kulkarni <[email protected]> > --- > drivers/gpu/drm/i915/display/icl_dsi.c | 40 ++++++++++++-------------- > 1 file changed, 19 insertions(+), 21 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c > b/drivers/gpu/drm/i915/display/icl_dsi.c > index 43ec7fcd3f5d..1780830d9909 100644 > --- a/drivers/gpu/drm/i915/display/icl_dsi.c > +++ b/drivers/gpu/drm/i915/display/icl_dsi.c > @@ -54,20 +54,28 @@ static int payload_credits_available(struct > drm_i915_private *dev_priv, > >> FREE_PLOAD_CREDIT_SHIFT; > } > > -static void wait_for_header_credits(struct drm_i915_private *dev_priv, > - enum transcoder dsi_trans) > +static bool wait_for_header_credits(struct drm_i915_private *dev_priv, > + enum transcoder dsi_trans, int hdr_credit) > { > if (wait_for_us(header_credits_available(dev_priv, dsi_trans) >= > - MAX_HEADER_CREDIT, 100)) > + hdr_credit, 100)) { > drm_err(&dev_priv->drm, "DSI header credits not > released\n"); > + return false; > + } > + > + return true; > } > > -static void wait_for_payload_credits(struct drm_i915_private *dev_priv, > - enum transcoder dsi_trans) > +static bool wait_for_payload_credits(struct drm_i915_private *dev_priv, > + enum transcoder dsi_trans, int > payld_credit) > { > if (wait_for_us(payload_credits_available(dev_priv, dsi_trans) >= > - MAX_PLOAD_CREDIT, 100)) > + payld_credit, 100)) { > drm_err(&dev_priv->drm, "DSI payload credits not > released\n"); > + return false; > + } > + > + return true; > } > > static enum transcoder dsi_port_to_transcoder(enum port port) @@ -90,8 > +98,8 @@ static void wait_for_cmds_dispatched_to_panel(struct > intel_encoder *encoder) > /* wait for header/payload credits to be released */ > for_each_dsi_port(port, intel_dsi->ports) { > dsi_trans = dsi_port_to_transcoder(port); > - wait_for_header_credits(dev_priv, dsi_trans); > - wait_for_payload_credits(dev_priv, dsi_trans); > + wait_for_header_credits(dev_priv, dsi_trans, > MAX_HEADER_CREDIT); > + wait_for_payload_credits(dev_priv, dsi_trans, > MAX_PLOAD_CREDIT); > } > > /* send nop DCS command */ > @@ -108,7 +116,7 @@ static void > wait_for_cmds_dispatched_to_panel(struct intel_encoder *encoder) > /* wait for header credits to be released */ > for_each_dsi_port(port, intel_dsi->ports) { > dsi_trans = dsi_port_to_transcoder(port); > - wait_for_header_credits(dev_priv, dsi_trans); > + wait_for_header_credits(dev_priv, dsi_trans, > MAX_HEADER_CREDIT); > } > > /* wait for LP TX in progress bit to be cleared */ @@ -126,18 +134,13 > @@ static bool add_payld_to_queue(struct intel_dsi_host *host, const u8 > *data, > struct intel_dsi *intel_dsi = host->intel_dsi; > struct drm_i915_private *dev_priv = to_i915(intel_dsi- > >base.base.dev); > enum transcoder dsi_trans = dsi_port_to_transcoder(host->port); > - int free_credits; > int i, j; > > for (i = 0; i < len; i += 4) { > u32 tmp = 0; > > - free_credits = payload_credits_available(dev_priv, > dsi_trans); > - if (free_credits < 1) { > - drm_err(&dev_priv->drm, > - "Payload credit not available\n"); > + if (!wait_for_payload_credits(dev_priv, dsi_trans, 1)) > return false; > - } > > for (j = 0; j < min_t(u32, len - i, 4); j++) > tmp |= *data++ << 8 * j; > @@ -155,15 +158,10 @@ static int dsi_send_pkt_hdr(struct intel_dsi_host > *host, > struct drm_i915_private *dev_priv = to_i915(intel_dsi- > >base.base.dev); > enum transcoder dsi_trans = dsi_port_to_transcoder(host->port); > u32 tmp; > - int free_credits; > > /* check if header credit available */ > - free_credits = header_credits_available(dev_priv, dsi_trans); > - if (free_credits < 1) { > - drm_err(&dev_priv->drm, > - "send pkt header failed, not enough hdr credits\n"); > + if (!wait_for_header_credits(dev_priv, dsi_trans, 1)) > return -1; > - } > > tmp = intel_de_read(dev_priv, DSI_CMD_TXHDR(dsi_trans)); > > -- > 2.17.1
