linux-kernel - [PATCH v3 3/5] mei: gsc: setup char driver alive in spite of firmware handshake failure

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Message-Id: <20220120145351.520555-4-alexander.usyskin@intel.com>
Date:   Thu, 20 Jan 2022 16:53:49 +0200
From:   Alexander Usyskin <alexander.usyskin@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     Tomas Winkler <tomas.winkler@...el.com>,
        Alexander Usyskin <alexander.usyskin@...el.com>,
        Vitaly Lubart <vitaly.lubart@...el.com>,
        intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH v3 3/5] mei: gsc: setup char driver alive in spite of firmware handshake failure

Setup char device in spite of firmware handshake failure.
In order to provide host access to the firmware status registers and other
information required for the manufacturing process.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/gsc-me.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/mei/gsc-me.c b/drivers/misc/mei/gsc-me.c
index 8673ad5f0015..f58e54d2c1fc 100644
--- a/drivers/misc/mei/gsc-me.c
+++ b/drivers/misc/mei/gsc-me.c
@@ -79,11 +79,12 @@ static int mei_gsc_probe(struct auxiliary_device *aux_dev,
 	pm_runtime_set_active(device);
 	pm_runtime_enable(device);
 
-	if (mei_start(dev)) {
-		dev_err(device, "init hw failure.\n");
-		ret = -ENODEV;
-		goto err;
-	}
+	/* Continue to char device setup in spite of firmware handshake failure.
+	 * In order to provide access to the firmware status registers to the user
+	 * space via sysfs.
+	 */
+	if (mei_start(dev))
+		dev_warn(device, "init hw failure.\n");
 
 	pm_runtime_set_autosuspend_delay(device, MEI_GSC_RPM_TIMEOUT);
 	pm_runtime_use_autosuspend(device);
-- 
2.32.0