Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 104C73B8409; Mon, 17 Aug 2026 14:26:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976769; cv=none; b=ANkV78dDTZS8jzGrDjGj/BpUDyiy4KJXAdGvUcfYBXEMSP2KmwyqFROTCRxj2fFQhunt8Mmgbnk91SsnnfNSI0nC1wDakKObH3OoZKvurfo309DeoJqluEMmLA4PNHYlZOf/aqGdLqs/WheA4zL/6YSF7dxMoxWGnMnuzHcknbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976769; c=relaxed/simple; bh=/pcQXpF00rfluWCSblvEeqz4Trk/9nrWOum5wc+D6Dg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kl1W2vVGrJ2vJQ5BaT34DF62ZA+g1UsrrXgZfCqLXFOY7c/h8sXQE+69zoUpnupk/vncfQ7BpGBHU6ixMv1cT97R/2Ns04RHlbETnLCxC5oGIEmGR2Lt10VkmXWoQsG79hOmHYmLW4JZ7Mhgfh9kYT0hOFVJ2GlPhNK/CiJV1xw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vMt6EEdz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vMt6EEdz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66B8B1F000E9; Mon, 17 Aug 2026 14:26:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786976768; bh=FT6vvVRXDSrYNsN+bC2hpwx7N0TFCjJyCBGj40WNMFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vMt6EEdzKN1Q9B+4DtzCtDfgEgWW35mXappymm14wSu/Thz3kWo+Y8KKMliUVX9zN g0FUnKUZ9M8q9gpbcwU3b76AAj3zzxL8l5hQIWdPJSDv7C4dLKp9Nyqk3mHhUoBae2 fIHdnqlpYSyAdXUi6KFBca4NYDlKG+7N/vdxDIEk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eddie James , Guenter Roeck , Sasha Levin Subject: [PATCH 5.15 096/456] hwmon: (occ) Delay hwmon registration until user request Date: Mon, 17 Aug 2026 15:28:06 +0200 Message-ID: <20260817132543.857639626@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eddie James [ Upstream commit 849b0156d9960da628a06756bb920d9571c15e66 ] Instead of registering the hwmon device at probe time, use the existing "occ_active" sysfs file to control when the driver polls the OCC for sensor data and registers with hwmon. The reason for this change is that the SBE, which is the device by which the driver communicates with the OCC, cannot handle communications during certain system state transitions, resulting in unrecoverable system errors. Signed-off-by: Eddie James Link: https://lore.kernel.org/r/20220427140443.11428-1-eajames@linux.ibm.com Signed-off-by: Guenter Roeck Stable-dep-of: 70e76e700fc6 ("hwmon: occ: validate poll response sensor blocks") Signed-off-by: Sasha Levin --- drivers/hwmon/occ/common.c | 100 +++++++++++++++++++-------- drivers/hwmon/occ/common.h | 5 +- drivers/hwmon/occ/p8_i2c.c | 2 +- drivers/hwmon/occ/p9_sbe.c | 2 +- drivers/hwmon/occ/sysfs.c | 137 ++++++++++++++++++++++--------------- 5 files changed, 156 insertions(+), 90 deletions(-) diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c index dff19885851220..e0ab04b1d92ca5 100644 --- a/drivers/hwmon/occ/common.c +++ b/drivers/hwmon/occ/common.c @@ -1106,44 +1106,75 @@ static void occ_parse_poll_response(struct occ *occ) sizeof(*header), size + sizeof(*header)); } -int occ_setup(struct occ *occ, const char *name) +int occ_active(struct occ *occ, bool active) { - int rc; - - mutex_init(&occ->lock); - occ->groups[0] = &occ->group; + int rc = mutex_lock_interruptible(&occ->lock); - /* no need to lock */ - rc = occ_poll(occ); - if (rc == -ESHUTDOWN) { - dev_info(occ->bus_dev, "host is not ready\n"); - return rc; - } else if (rc < 0) { - dev_err(occ->bus_dev, - "failed to get OCC poll response=%02x: %d\n", - occ->resp.return_status, rc); + if (rc) return rc; - } - occ->next_update = jiffies + OCC_UPDATE_FREQUENCY; - occ_parse_poll_response(occ); + if (active) { + if (occ->active) { + rc = -EALREADY; + goto unlock; + } - rc = occ_setup_sensor_attrs(occ); - if (rc) { - dev_err(occ->bus_dev, "failed to setup sensor attrs: %d\n", - rc); - return rc; - } + occ->error_count = 0; + occ->last_safe = 0; - occ->hwmon = devm_hwmon_device_register_with_groups(occ->bus_dev, name, - occ, occ->groups); - if (IS_ERR(occ->hwmon)) { - rc = PTR_ERR(occ->hwmon); - dev_err(occ->bus_dev, "failed to register hwmon device: %d\n", - rc); - return rc; + rc = occ_poll(occ); + if (rc < 0) { + dev_err(occ->bus_dev, + "failed to get OCC poll response=%02x: %d\n", + occ->resp.return_status, rc); + goto unlock; + } + + occ->active = true; + occ->next_update = jiffies + OCC_UPDATE_FREQUENCY; + occ_parse_poll_response(occ); + + rc = occ_setup_sensor_attrs(occ); + if (rc) { + dev_err(occ->bus_dev, + "failed to setup sensor attrs: %d\n", rc); + goto unlock; + } + + occ->hwmon = hwmon_device_register_with_groups(occ->bus_dev, + "occ", occ, + occ->groups); + if (IS_ERR(occ->hwmon)) { + rc = PTR_ERR(occ->hwmon); + occ->hwmon = NULL; + dev_err(occ->bus_dev, + "failed to register hwmon device: %d\n", rc); + goto unlock; + } + } else { + if (!occ->active) { + rc = -EALREADY; + goto unlock; + } + + if (occ->hwmon) + hwmon_device_unregister(occ->hwmon); + occ->active = false; + occ->hwmon = NULL; } +unlock: + mutex_unlock(&occ->lock); + return rc; +} + +int occ_setup(struct occ *occ) +{ + int rc; + + mutex_init(&occ->lock); + occ->groups[0] = &occ->group; + rc = occ_setup_sysfs(occ); if (rc) dev_err(occ->bus_dev, "failed to setup sysfs: %d\n", rc); @@ -1152,6 +1183,15 @@ int occ_setup(struct occ *occ, const char *name) } EXPORT_SYMBOL_GPL(occ_setup); +void occ_shutdown(struct occ *occ) +{ + occ_shutdown_sysfs(occ); + + if (occ->hwmon) + hwmon_device_unregister(occ->hwmon); +} +EXPORT_SYMBOL_GPL(occ_shutdown); + MODULE_AUTHOR("Eddie James "); MODULE_DESCRIPTION("Common OCC hwmon code"); MODULE_LICENSE("GPL"); diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h index 726943af9a077e..7ac4b2febce65f 100644 --- a/drivers/hwmon/occ/common.h +++ b/drivers/hwmon/occ/common.h @@ -107,6 +107,7 @@ struct occ { struct attribute_group group; const struct attribute_group *groups[2]; + bool active; int error; /* final transfer error after retry */ int last_error; /* latest transfer error */ unsigned int error_count; /* number of xfr errors observed */ @@ -124,9 +125,11 @@ struct occ { u8 prev_mode; }; -int occ_setup(struct occ *occ, const char *name); +int occ_active(struct occ *occ, bool active); +int occ_setup(struct occ *occ); int occ_setup_sysfs(struct occ *occ); void occ_shutdown(struct occ *occ); +void occ_shutdown_sysfs(struct occ *occ); void occ_sysfs_poll_done(struct occ *occ); int occ_update_response(struct occ *occ); diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c index c35c07964d856c..b221be1f35f31e 100644 --- a/drivers/hwmon/occ/p8_i2c.c +++ b/drivers/hwmon/occ/p8_i2c.c @@ -224,7 +224,7 @@ static int p8_i2c_occ_probe(struct i2c_client *client) occ->poll_cmd_data = 0x10; /* P8 OCC poll data */ occ->send_cmd = p8_i2c_occ_send_cmd; - return occ_setup(occ, "p8_occ"); + return occ_setup(occ); } static int p8_i2c_occ_remove(struct i2c_client *client) diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c index 14923e78e1f324..3c3d887fcc1e04 100644 --- a/drivers/hwmon/occ/p9_sbe.c +++ b/drivers/hwmon/occ/p9_sbe.c @@ -73,7 +73,7 @@ static int p9_sbe_occ_probe(struct platform_device *pdev) occ->poll_cmd_data = 0x20; /* P9 OCC poll data */ occ->send_cmd = p9_sbe_occ_send_cmd; - rc = occ_setup(occ, "p9_occ"); + rc = occ_setup(occ); if (rc == -ESHUTDOWN) rc = -ENODEV; /* Host is shutdown, don't spew errors */ diff --git a/drivers/hwmon/occ/sysfs.c b/drivers/hwmon/occ/sysfs.c index b2f788a7774693..2317301fc1e9f6 100644 --- a/drivers/hwmon/occ/sysfs.c +++ b/drivers/hwmon/occ/sysfs.c @@ -6,13 +6,13 @@ #include #include #include +#include #include #include "common.h" /* OCC status register */ #define OCC_STAT_MASTER BIT(7) -#define OCC_STAT_ACTIVE BIT(0) /* OCC extended status register */ #define OCC_EXT_STAT_DVFS_OT BIT(7) @@ -22,6 +22,25 @@ #define OCC_EXT_STAT_DVFS_VDD BIT(3) #define OCC_EXT_STAT_GPU_THROTTLE GENMASK(2, 0) +static ssize_t occ_active_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int rc; + bool active; + struct occ *occ = dev_get_drvdata(dev); + + rc = kstrtobool(buf, &active); + if (rc) + return rc; + + rc = occ_active(occ, active); + if (rc) + return rc; + + return count; +} + static ssize_t occ_sysfs_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -31,54 +50,64 @@ static ssize_t occ_sysfs_show(struct device *dev, struct occ_poll_response_header *header; struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); - rc = occ_update_response(occ); - if (rc) - return rc; + if (occ->active) { + rc = occ_update_response(occ); + if (rc) + return rc; - header = (struct occ_poll_response_header *)occ->resp.data; - - switch (sattr->index) { - case 0: - val = !!(header->status & OCC_STAT_MASTER); - break; - case 1: - val = !!(header->status & OCC_STAT_ACTIVE); - break; - case 2: - val = !!(header->ext_status & OCC_EXT_STAT_DVFS_OT); - break; - case 3: - val = !!(header->ext_status & OCC_EXT_STAT_DVFS_POWER); - break; - case 4: - val = !!(header->ext_status & OCC_EXT_STAT_MEM_THROTTLE); - break; - case 5: - val = !!(header->ext_status & OCC_EXT_STAT_QUICK_DROP); - break; - case 6: - val = header->occ_state; - break; - case 7: - if (header->status & OCC_STAT_MASTER) - val = hweight8(header->occs_present); - else + header = (struct occ_poll_response_header *)occ->resp.data; + + switch (sattr->index) { + case 0: + val = !!(header->status & OCC_STAT_MASTER); + break; + case 1: val = 1; - break; - case 8: - val = header->ips_status; - break; - case 9: - val = header->mode; - break; - case 10: - val = !!(header->ext_status & OCC_EXT_STAT_DVFS_VDD); - break; - case 11: - val = header->ext_status & OCC_EXT_STAT_GPU_THROTTLE; - break; - default: - return -EINVAL; + break; + case 2: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_OT); + break; + case 3: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_POWER); + break; + case 4: + val = !!(header->ext_status & + OCC_EXT_STAT_MEM_THROTTLE); + break; + case 5: + val = !!(header->ext_status & OCC_EXT_STAT_QUICK_DROP); + break; + case 6: + val = header->occ_state; + break; + case 7: + if (header->status & OCC_STAT_MASTER) + val = hweight8(header->occs_present); + else + val = 1; + break; + case 8: + val = header->ips_status; + break; + case 9: + val = header->mode; + break; + case 10: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_VDD); + break; + case 11: + val = header->ext_status & OCC_EXT_STAT_GPU_THROTTLE; + break; + default: + return -EINVAL; + } + } else { + if (sattr->index == 1) + val = 0; + else if (sattr->index <= 11) + val = -ENODATA; + else + return -EINVAL; } return sysfs_emit(buf, "%d\n", val); @@ -95,7 +124,8 @@ static ssize_t occ_error_show(struct device *dev, } static SENSOR_DEVICE_ATTR(occ_master, 0444, occ_sysfs_show, NULL, 0); -static SENSOR_DEVICE_ATTR(occ_active, 0444, occ_sysfs_show, NULL, 1); +static SENSOR_DEVICE_ATTR(occ_active, 0644, occ_sysfs_show, occ_active_store, + 1); static SENSOR_DEVICE_ATTR(occ_dvfs_overtemp, 0444, occ_sysfs_show, NULL, 2); static SENSOR_DEVICE_ATTR(occ_dvfs_power, 0444, occ_sysfs_show, NULL, 3); static SENSOR_DEVICE_ATTR(occ_mem_throttle, 0444, occ_sysfs_show, NULL, 4); @@ -139,7 +169,7 @@ void occ_sysfs_poll_done(struct occ *occ) * On the first poll response, we haven't yet created the sysfs * attributes, so don't make any notify calls. */ - if (!occ->hwmon) + if (!occ->active) goto done; if ((header->status & OCC_STAT_MASTER) != @@ -148,12 +178,6 @@ void occ_sysfs_poll_done(struct occ *occ) sysfs_notify(&occ->bus_dev->kobj, NULL, name); } - if ((header->status & OCC_STAT_ACTIVE) != - (occ->prev_stat & OCC_STAT_ACTIVE)) { - name = sensor_dev_attr_occ_active.dev_attr.attr.name; - sysfs_notify(&occ->bus_dev->kobj, NULL, name); - } - if ((header->ext_status & OCC_EXT_STAT_DVFS_OT) != (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_OT)) { name = sensor_dev_attr_occ_dvfs_overtemp.dev_attr.attr.name; @@ -227,8 +251,7 @@ int occ_setup_sysfs(struct occ *occ) return sysfs_create_group(&occ->bus_dev->kobj, &occ_sysfs); } -void occ_shutdown(struct occ *occ) +void occ_shutdown_sysfs(struct occ *occ) { sysfs_remove_group(&occ->bus_dev->kobj, &occ_sysfs); } -EXPORT_SYMBOL_GPL(occ_shutdown); -- 2.53.0