[PATCH] drm/amd/display: disable FPO and SubVP for older DMUB versions on DCN32x

[Hamza Mahfooz]

There have recently been changes that break backwards compatibility,
that were introduced into DMUB firmware (for DCN32x) concerning FPO and
SubVP. So, since those are just power optimization features, we can just
disable them unless the user is using a new enough version of DMUB
firmware.

Cc: stable at vger.kernel.org
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2870
Fixes: ed6e2782e974 ("drm/amd/display: For cursor P-State allow for SubVP")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov at gmail.com>
Closes: https://lore.kernel.org/r/CABXGCsNRb0QbF2pKLJMDhVOKxyGD6-E+8p-4QO6FOWa6zp22_A@mail.gmail.com/
Signed-off-by: Hamza Mahfooz <hamza.mahfooz at amd.com>
---
 drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c
index 5c323718ec90..0f0972ad441a 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn32/dcn32_hwseq.c
@@ -960,6 +960,12 @@ void dcn32_init_hw(struct dc *dc)
 		dc->caps.dmub_caps.subvp_psr = dc->ctx->dmub_srv->dmub->feature_caps.subvp_psr_support;
 		dc->caps.dmub_caps.gecc_enable = dc->ctx->dmub_srv->dmub->feature_caps.gecc_enable;
 		dc->caps.dmub_caps.mclk_sw = dc->ctx->dmub_srv->dmub->feature_caps.fw_assisted_mclk_switch;
+
+		if (dc->ctx->dmub_srv->dmub->fw_version <
+		    DMUB_FW_VERSION(7, 0, 35)) {
+			dc->debug.force_disable_subvp = true;
+			dc->debug.disable_fpo_optimizations = true;
+		}
 	}
 }
 
-- 
2.43.0