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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Daniel Wheeler <daniel.wheeler@amd.com>,
        Wyatt Wood <wyatt.wood@amd.com>,
        Anthony Koo <Anthony.Koo@amd.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 151/384] drm/amd/display: Return invalid state if GPINT times out
Date:   Mon, 10 May 2021 12:19:00 +0200
Message-Id: <20210510102019.860700735@linuxfoundation.org>
In-Reply-To: <20210510102014.849075526@linuxfoundation.org>
References: <20210510102014.849075526@linuxfoundation.org>
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From: Wyatt Wood <wyatt.wood@amd.com>

[ Upstream commit 8039bc7130ef4206a58e4dc288621bc97eba08eb ]

[Why]
GPINT timeout is causing PSR_STATE_0 to be returned when it shouldn't.
We must guarantee that PSR is fully disabled before doing hw programming
on driver-side.

[How]
Return invalid state if GPINT command times out. Let existing retry
logic send the GPINT until successful.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
index 69e34bef274c..febccb35ddad 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -81,13 +81,18 @@ static void dmub_psr_get_state(struct dmub_psr *dmub, enum dc_psr_state *state)
 {
 	struct dmub_srv *srv = dmub->ctx->dmub_srv->dmub;
 	uint32_t raw_state;
+	enum dmub_status status = DMUB_STATUS_INVALID;
 
 	// Send gpint command and wait for ack
-	dmub_srv_send_gpint_command(srv, DMUB_GPINT__GET_PSR_STATE, 0, 30);
-
-	dmub_srv_get_gpint_response(srv, &raw_state);
-
-	*state = convert_psr_state(raw_state);
+	status = dmub_srv_send_gpint_command(srv, DMUB_GPINT__GET_PSR_STATE, 0, 30);
+
+	if (status == DMUB_STATUS_OK) {
+		// GPINT was executed, get response
+		dmub_srv_get_gpint_response(srv, &raw_state);
+		*state = convert_psr_state(raw_state);
+	} else
+		// Return invalid state when GPINT times out
+		*state = 0xFF;
 }
 
 /*
-- 
2.30.2