From nobody Sun May 24 19:34:22 2026 Received: from mail-ej1-f52.google.com (mail-ej1-f52.google.com [209.85.218.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6770546AF1A for ; Fri, 22 May 2026 15:45:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.52 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779464705; cv=none; b=CVsNKzL6wN0xjGn1tTRtUAsGsNU1Qz2whs4R40Ipqm8kZgRBZrBkyVi33G4HDApeCeH66OgOnPDqOcFTAdEL7C9M65HIcXDIktio1uM2mn3geNSgMr/sGnL8N2XZkVNvEz66Ls4XEdORn7JmRxzeUY55VQrrXaS6ZKzsbajRsfU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779464705; c=relaxed/simple; bh=eyYt1g/Y58tXmMeO8f3HJ9YXJ3oT3Rw0BmK7dmkQ8PY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lenvL+3JH2G5GkjKdwWzUMrQsproeG+Mu/BT5A0n7Xh8w4MOG78Uc2dqFNz9jsrRnLzLM/9Qwdgy8XNiyZLELNQgHw/pIJNZWobyKzxa1h4MHb2d9E344Kcybttp1oDuoDj57/ftOifVOv9gZByovFRBGpDYuFh6hPO0aZd2XJs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=b5FA+wcr; arc=none smtp.client-ip=209.85.218.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="b5FA+wcr" Received: by mail-ej1-f52.google.com with SMTP id a640c23a62f3a-bd56d108454so1419571266b.2 for ; Fri, 22 May 2026 08:45:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1779464702; x=1780069502; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Sn9ZWX/LHdvsmMbuXtFnELWJ9oecMT6d7N6qyRp7Au0=; b=b5FA+wcrB6o7xJrAAXgSiU5BOnNoZ4VDWeAtLtH2jxTahWlHRICbhm1bdAdGb2dzFP dpQI1fSZSV5857ont1voe0Gg2IavA26kNHr8Z6RQOvXgZW0nkSiqsBazd+o1PaPnf7A0 Y/Gyk0NsvUmUdWYBkfXexVk0VFVs8G+HEQpck= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779464702; x=1780069502; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Sn9ZWX/LHdvsmMbuXtFnELWJ9oecMT6d7N6qyRp7Au0=; b=OFPq0kFSPlOCfJlqMWO4SfS3OvsFfYtj6/Yg6yWojEXviJBgkQuKSp+7KO7h7iAmdC D6SiRAGqNPOkz3Egr463ftJ9f1AgYnUo2ZkkBftDMpPP7+TxgNJiZ8KGE/Bczp4QJle7 lWvX+Tn95hpBudwtzwIKGs70xHj6HTaEBHwMVmM58f2ngAy4W0d5+n1o2OozdjoJ36zM P2cL7AvCWXBBqnVThVEedBSJQeBmWM90eI34ZOjTpTVugUKGwe4S/fDtk7p19WXZQmJ1 BHSaph9cYZVc4fGIg40x48xV58B5fY+LB5Y6YK/GYw8aeWML58NWvqjgdXD/WEC2sxWf AO0A== X-Forwarded-Encrypted: i=1; AFNElJ/7Y/wPkCYBVUJAlKJunMjNeBOt5phDi/k7SButDpUFW/IjclZ8JkJwgmdDFOmUQ9rvQ1RbIVwYm9zcKBE=@vger.kernel.org X-Gm-Message-State: AOJu0YzRXkBeYMnV5QQXtPfqJu7HhjNG7/vLjxgILZa7Azsmvs0H5Bni hKqKMmwqeYoFsPIKF40xDrzP/7fSCN7cNORahdl4d/pxo7iTl9gLVWmExETJX1TFMA== X-Gm-Gg: Acq92OEWaqXOvQd2DeuOYIN/ZHhwMRd/m0HcwVcFQCggC28s8pocH8D8IgwgM7Xn91r NiXwtkmk0kS//YBn5E+UrIW9PawNHN4Qyq5WzdhXDlDnfNB+QpQKhlKWnSrBkylytbMn0SXspSZ wu80KbV13MHOyDfjHpa9moyfe8B36bShXpYtPKOAGD2jVjVofVeDasMYmyWq05kn6sSAGe113Ke oH+zqkQtl8XT+gRXhKkb1DrgnreZ2VehUwM+fe0j6XC/paVkK5Jdvkjz5dBS/fH3R/lmjDS5we+ cF6iZRcLeZixUF6OKg8Chr1450rSnY+d+uyJHqzt45fUyfsG2yFf1r1XrPPI+9BT20qmIuAlhTA LoQq0aGtdlupNqL4dWtmo/I9QR0K8N2gSqJPEz70afEivyOmQhji900pe4ggxLkpS3gjOW1OYax SubwEFDduc+E1hPRLBuDk8dBAD85RMTe+UQNWDPdckrWNNK0kBXlQa0O/wAhcTh/ZKyNZcMTZkR /Rm94vkuRPuqkRvenCQ X-Received: by 2002:a17:907:b80c:b0:bde:137a:45a8 with SMTP id a640c23a62f3a-bde137a477fmr90203466b.39.1779464701838; Fri, 22 May 2026 08:45:01 -0700 (PDT) Received: from akuchynski.c.googlers.com.com (208.220.32.34.bc.googleusercontent.com. [34.32.220.208]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-bddc62d635bsm68907266b.47.2026.05.22.08.45.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 May 2026 08:45:01 -0700 (PDT) From: Andrei Kuchynski To: Lee Jones , Benson Leung , Tzung-Bi Shih Cc: Guenter Roeck , Gwendal Grignou , chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org, Andrei Kuchynski Subject: [PATCH] mfd: cros_ec: Read EC features during probe to catch transfer error Date: Fri, 22 May 2026 15:44:56 +0000 Message-ID: <20260522154456.1448170-1-akuchynski@chromium.org> X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" cros_ec_check_features() does not return an error if the underlying EC_CMD_GET_FEATURES command fails. Consequently, when the Fingerprint device fails to respond, the probe function ignores the failure and falls back to installing it as 'cros_ec' device instead of 'cros_fp'. This leads to a sysfs duplicate filename collision later when the real 'cros_ec' device attempts to register: cros-ec-spi spi5.0: EC failed to respond in time cros-ec-dev.19.auto: cannot get EC features: -110 sysfs : cannot create duplicate filename '/class/chromeos/cros_ec' : sysfs_do_create_link_sd+0x94/0xdc : ec_device_probe+0x150/0x4f0 Fix this by extracting the feature reading logic into a new helper function cros_ec_read_features() and calling it during ec_device_probe(). If the transfer fails, abort the broken device initialization. Signed-off-by: Andrei Kuchynski --- drivers/mfd/cros_ec_dev.c | 4 +++ drivers/platform/chrome/cros_ec_proto.c | 30 +++++++++++++++------ include/linux/platform_data/cros_ec_proto.h | 2 ++ 3 files changed, 28 insertions(+), 8 deletions(-) diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c index 39430dd44e30c..7810b1c871849 100644 --- a/drivers/mfd/cros_ec_dev.c +++ b/drivers/mfd/cros_ec_dev.c @@ -203,6 +203,10 @@ static int ec_device_probe(struct platform_device *pde= v) ec->features.flags[1] =3D -1U; /* Not cached yet */ device_initialize(&ec->class_dev); =20 + retval =3D cros_ec_read_features(ec); + if (retval < 0) + return retval; + for (i =3D 0; i < ARRAY_SIZE(cros_mcu_devices); i++) { /* * Check whether this is actually a dedicated MCU rather diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chr= ome/cros_ec_proto.c index 1d8d9168ec1aa..724d1313f6b21 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -946,6 +946,27 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_d= ev) } EXPORT_SYMBOL(cros_ec_get_host_event); =20 +/** + * cros_ec_read_features() - Read EC features + * + * @ec: EC device. + * + * Return: >=3D 0 on success, negative error number on failure. + */ +int cros_ec_read_features(struct cros_ec_dev *ec) +{ + int ret =3D cros_ec_cmd(ec->ec_dev, 0, EC_CMD_GET_FEATURES + ec->cmd_offs= et, + NULL, 0, &ec->features, sizeof(ec->features)); + + if (ret < 0) { + dev_warn(ec->dev, "cannot get EC features: %d\n", ret); + memset(&ec->features, 0, sizeof(ec->features)); + } + + return ret; +} +EXPORT_SYMBOL_GPL(cros_ec_read_features); + /** * cros_ec_check_features() - Test for the presence of EC features * @@ -960,17 +981,10 @@ EXPORT_SYMBOL(cros_ec_get_host_event); bool cros_ec_check_features(struct cros_ec_dev *ec, int feature) { struct ec_response_get_features *features =3D &ec->features; - int ret; =20 if (features->flags[0] =3D=3D -1U && features->flags[1] =3D=3D -1U) { /* features bitmap not read yet */ - ret =3D cros_ec_cmd(ec->ec_dev, 0, EC_CMD_GET_FEATURES + ec->cmd_offset, - NULL, 0, features, sizeof(*features)); - if (ret < 0) { - dev_warn(ec->dev, "cannot get EC features: %d\n", ret); - memset(features, 0, sizeof(*features)); - } - + cros_ec_read_features(ec); dev_dbg(ec->dev, "EC features %08x %08x\n", features->flags[0], features->flags[1]); } diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/pl= atform_data/cros_ec_proto.h index 6ed1c4c5ce2ef..a1ccecf5e1f83 100644 --- a/include/linux/platform_data/cros_ec_proto.h +++ b/include/linux/platform_data/cros_ec_proto.h @@ -271,6 +271,8 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_de= v, =20 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev); =20 +int cros_ec_read_features(struct cros_ec_dev *ec); + bool cros_ec_check_features(struct cros_ec_dev *ec, int feature); =20 int cros_ec_get_sensor_count(struct cros_ec_dev *ec); --=20 2.54.0.746.g67dd491aae-goog