diff options
Diffstat (limited to 'drivers/gpu/drm/xlnx/zynqmp_dp.c')
| -rw-r--r-- | drivers/gpu/drm/xlnx/zynqmp_dp.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index b735072a702d..99158ee67d02 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -567,34 +567,37 @@ static int zynqmp_dp_mode_configure(struct zynqmp_dp *dp, int pclock, u8 current_bw) { int max_rate = dp->link_config.max_rate; - u8 bws[3] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7, DP_LINK_BW_5_4 }; + u8 bw_code; u8 max_lanes = dp->link_config.max_lanes; u8 max_link_rate_code = drm_dp_link_rate_to_bw_code(max_rate); u8 bpp = dp->config.bpp; u8 lane_cnt; - s8 i; - if (current_bw == DP_LINK_BW_1_62) { + /* Downshift from current bandwidth */ + switch (current_bw) { + case DP_LINK_BW_5_4: + bw_code = DP_LINK_BW_2_7; + break; + case DP_LINK_BW_2_7: + bw_code = DP_LINK_BW_1_62; + break; + case DP_LINK_BW_1_62: dev_err(dp->dev, "can't downshift. already lowest link rate\n"); return -EINVAL; - } - - for (i = ARRAY_SIZE(bws) - 1; i >= 0; i--) { - if (current_bw && bws[i] >= current_bw) - continue; - - if (bws[i] <= max_link_rate_code) - break; + default: + /* If not given, start with max supported */ + bw_code = max_link_rate_code; + break; } for (lane_cnt = 1; lane_cnt <= max_lanes; lane_cnt <<= 1) { int bw; u32 rate; - bw = drm_dp_bw_code_to_link_rate(bws[i]); + bw = drm_dp_bw_code_to_link_rate(bw_code); rate = zynqmp_dp_max_rate(bw, lane_cnt, bpp); if (pclock <= rate) { - dp->mode.bw_code = bws[i]; + dp->mode.bw_code = bw_code; dp->mode.lane_cnt = lane_cnt; dp->mode.pclock = pclock; return dp->mode.bw_code; |