From: Tzung-Bi Shih Date: Mon, 25 May 2026 05:26:52 +0000 (+0000) Subject: platform/chrome: cros_ec_chardev: Move data to chardev_pdata X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74aa0d4008051878c632530f2a2c13cff8e9b171;p=thirdparty%2Flinux.git platform/chrome: cros_ec_chardev: Move data to chardev_pdata Move `ec_dev` and `cmd_offset` from `chardev_priv` to `chardev_pdata` as they are per-device properties but not per-open-file properties. Hold a reference to `chardev_pdata` for each open file to ensure the data remains valid even if the underlying platform device is removed. Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20260525052654.4076429-3-tzungbi@kernel.org Signed-off-by: Tzung-Bi Shih --- diff --git a/drivers/platform/chrome/cros_ec_chardev.c b/drivers/platform/chrome/cros_ec_chardev.c index e7012e44a006a..352d61a2f3c6e 100644 --- a/drivers/platform/chrome/cros_ec_chardev.c +++ b/drivers/platform/chrome/cros_ec_chardev.c @@ -38,6 +38,8 @@ struct chardev_pdata { struct miscdevice misc; struct kref kref; + struct cros_ec_device *ec_dev; + u16 cmd_offset; }; static void chardev_pdata_release(struct kref *kref) @@ -48,13 +50,12 @@ static void chardev_pdata_release(struct kref *kref) } struct chardev_priv { - struct cros_ec_device *ec_dev; struct notifier_block notifier; wait_queue_head_t wait_event; unsigned long event_mask; struct list_head events; size_t event_len; - u16 cmd_offset; + struct chardev_pdata *pdata; }; struct ec_event { @@ -77,10 +78,10 @@ static int ec_get_version(struct chardev_priv *priv, char *str, int maxlen) if (!msg) return -ENOMEM; - msg->command = EC_CMD_GET_VERSION + priv->cmd_offset; + msg->command = EC_CMD_GET_VERSION + priv->pdata->cmd_offset; msg->insize = sizeof(*resp); - ret = cros_ec_cmd_xfer_status(priv->ec_dev, msg); + ret = cros_ec_cmd_xfer_status(priv->pdata->ec_dev, msg); if (ret < 0) { snprintf(str, maxlen, "Unknown EC version, returned error: %d\n", @@ -108,7 +109,7 @@ static int cros_ec_chardev_mkbp_event(struct notifier_block *nb, { struct chardev_priv *priv = container_of(nb, struct chardev_priv, notifier); - struct cros_ec_device *ec_dev = priv->ec_dev; + struct cros_ec_device *ec_dev = priv->pdata->ec_dev; struct ec_event *event; unsigned long event_bit = 1 << ec_dev->event_data.event_type; int total_size = sizeof(*event) + ec_dev->event_size; @@ -173,8 +174,7 @@ out: static int cros_ec_chardev_open(struct inode *inode, struct file *filp) { struct miscdevice *mdev = filp->private_data; - struct cros_ec_dev *ec = dev_get_drvdata(mdev->parent); - struct cros_ec_device *ec_dev = ec->ec_dev; + struct chardev_pdata *pdata = container_of(mdev, typeof(*pdata), misc); struct chardev_priv *priv; int ret; @@ -182,18 +182,20 @@ static int cros_ec_chardev_open(struct inode *inode, struct file *filp) if (!priv) return -ENOMEM; - priv->ec_dev = ec_dev; - priv->cmd_offset = ec->cmd_offset; + priv->pdata = pdata; + kref_get(&pdata->kref); filp->private_data = priv; INIT_LIST_HEAD(&priv->events); init_waitqueue_head(&priv->wait_event); nonseekable_open(inode, filp); priv->notifier.notifier_call = cros_ec_chardev_mkbp_event; - ret = blocking_notifier_chain_register(&ec_dev->event_notifier, + ret = blocking_notifier_chain_register(&pdata->ec_dev->event_notifier, &priv->notifier); if (ret) { - dev_err(ec_dev->dev, "failed to register event notifier\n"); + dev_err(pdata->ec_dev->dev, + "failed to register event notifier\n"); + kref_put(&priv->pdata->kref, chardev_pdata_release); kfree(priv); } @@ -267,11 +269,11 @@ static ssize_t cros_ec_chardev_read(struct file *filp, char __user *buffer, static int cros_ec_chardev_release(struct inode *inode, struct file *filp) { struct chardev_priv *priv = filp->private_data; - struct cros_ec_device *ec_dev = priv->ec_dev; struct ec_event *event, *e; - blocking_notifier_chain_unregister(&ec_dev->event_notifier, + blocking_notifier_chain_unregister(&priv->pdata->ec_dev->event_notifier, &priv->notifier); + kref_put(&priv->pdata->kref, chardev_pdata_release); list_for_each_entry_safe(event, e, &priv->events, node) { list_del(&event->node); @@ -314,8 +316,8 @@ static long cros_ec_chardev_ioctl_xcmd(struct chardev_priv *priv, void __user *a goto exit; } - s_cmd->command += priv->cmd_offset; - ret = cros_ec_cmd_xfer(priv->ec_dev, s_cmd); + s_cmd->command += priv->pdata->cmd_offset; + ret = cros_ec_cmd_xfer(priv->pdata->ec_dev, s_cmd); /* Only copy data to userland if data was received. */ if (ret < 0) goto exit; @@ -329,7 +331,7 @@ exit: static long cros_ec_chardev_ioctl_readmem(struct chardev_priv *priv, void __user *arg) { - struct cros_ec_device *ec_dev = priv->ec_dev; + struct cros_ec_device *ec_dev = priv->pdata->ec_dev; struct cros_ec_readmem s_mem = { }; long num; @@ -399,6 +401,8 @@ static int cros_ec_chardev_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pdata); kref_init(&pdata->kref); + pdata->ec_dev = ec->ec_dev; + pdata->cmd_offset = ec->cmd_offset; pdata->misc.minor = MISC_DYNAMIC_MINOR; pdata->misc.fops = &chardev_fops;