From 081c2fc8b9cdd13a2436e8510889293874a33340 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Sun, 14 Oct 2007 02:52:17 -0300 Subject: [PATCH] V4L/DVB (6334): cx88: Change (struct cx8802_dev)->drvlist to a list_head and fix bugs It was a struct cx8802_driver for no apparent reason. Nothing uses a cx8802_driver in the cx8802_dev struct. The only field that was used was devlist, a list_head. The code in cx8802_remove() that removed any loaded sub-drivers was broken. It would delete the current list entry, but didn't use list_for_each_safe. It also called list_del() on the list _head_ inside the list_for_each loop? It would crash if it was run, which I don't think can ever happen. Since the cx8802 sub-drivers use the cx8802 driver, they have to be unloaded first. So there isn't any way for a sub-driver to still be loaded when cx8802_remove() is called... Except maybe with PCI hot-plug, if one removes the PCI card while the drivers are loaded? So I left some code in to handle that if it's actually possible. It will remove the sub-drivers from the device cx8802_remove() was called on, and only that device. If one has two DVB cards and unplugs one, there is no reason to unload the DVB drivers for both cards. I have no way to test this, but it can't be worse than what was there before. cx8802_get_driver() is passed a cx8802_dev pointer and looks for the requested driver on that device. It first loops over the cx8802 device list looking for the device it was passed, which is pointless. It doesn't need to find the device pointer in the list, as it already has the pointer. The list_head in the cx8802_driver struct, which joins all the _drivers_ attached to a device, was named devlist. Changed that to drvlist, since the devlist is used for a list of _devices_ in other cx8802 structs. Signed-off-by: Trent Piepho Reviewed-by: Michael Krufky Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/cx88/cx88-mpeg.c | 60 ++++++++++++++-------------- drivers/media/video/cx88/cx88.h | 8 ++-- 2 files changed, 34 insertions(+), 34 deletions(-) diff --git a/drivers/media/video/cx88/cx88-mpeg.c b/drivers/media/video/cx88/cx88-mpeg.c index 1b1418241b..11d9865e34 100644 --- a/drivers/media/video/cx88/cx88-mpeg.c +++ b/drivers/media/video/cx88/cx88-mpeg.c @@ -594,24 +594,14 @@ EXPORT_SYMBOL(cx8802_get_device); struct cx8802_driver * cx8802_get_driver(struct cx8802_dev *dev, enum cx88_board_type btype) { - struct cx8802_dev *h = NULL; - struct cx8802_driver *d = NULL; + struct cx8802_driver *d; struct list_head *list; - struct list_head *list2; - - list_for_each(list,&cx8802_devlist) { - h = list_entry(list, struct cx8802_dev, devlist); - if (h != dev) - continue; - list_for_each(list2, &h->drvlist.devlist) { - d = list_entry(list2, struct cx8802_driver, devlist); + list_for_each(list, &dev->drvlist) { + d = list_entry(list, struct cx8802_driver, drvlist); - /* only unregister the correct driver type */ - if (d->type_id == btype) { - return d; - } - } + if (d->type_id == btype) + return d; } return NULL; @@ -717,7 +707,7 @@ int cx8802_register_driver(struct cx8802_driver *drv) if (err == 0) { i++; mutex_lock(&drv->core->lock); - list_add_tail(&driver->devlist,&h->drvlist.devlist); + list_add_tail(&driver->drvlist, &h->drvlist); mutex_unlock(&drv->core->lock); } else { printk(KERN_ERR @@ -757,8 +747,8 @@ int cx8802_unregister_driver(struct cx8802_driver *drv) h->pci->subsystem_device, h->core->board.name, h->core->boardnr); - list_for_each_safe(list2, q, &h->drvlist.devlist) { - d = list_entry(list2, struct cx8802_driver, devlist); + list_for_each_safe(list2, q, &h->drvlist) { + d = list_entry(list2, struct cx8802_driver, drvlist); /* only unregister the correct driver type */ if (d->type_id != drv->type_id) @@ -772,7 +762,6 @@ int cx8802_unregister_driver(struct cx8802_driver *drv) } else printk(KERN_ERR "%s/2: cx8802 driver remove " "failed (%d)\n", h->core->name, err); - } } @@ -810,7 +799,7 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev, if (err != 0) goto fail_free; - INIT_LIST_HEAD(&dev->drvlist.devlist); + INIT_LIST_HEAD(&dev->drvlist); list_add_tail(&dev->devlist,&cx8802_devlist); /* Maintain a reference so cx88-video can query the 8802 device. */ @@ -830,23 +819,32 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev, static void __devexit cx8802_remove(struct pci_dev *pci_dev) { struct cx8802_dev *dev; - struct cx8802_driver *h; - struct list_head *list; dev = pci_get_drvdata(pci_dev); dprintk( 1, "%s\n", __FUNCTION__); - list_for_each(list,&dev->drvlist.devlist) { - h = list_entry(list, struct cx8802_driver, devlist); - dprintk( 1, " ->driver\n"); - if (h->remove == NULL) { - printk(KERN_ERR "%s .. skipping driver, no probe function\n", __FUNCTION__); - continue; + if (!list_empty(&dev->drvlist)) { + struct list_head *list, *tmp; + struct cx8802_driver *drv; + int err; + + printk(KERN_WARNING "%s/2: Trying to remove cx8802 driver " + "while cx8802 sub-drivers still loaded?!\n", + dev->core->name); + + list_for_each_safe(list, tmp, &dev->drvlist) { + drv = list_entry(list, struct cx8802_driver, drvlist); + + err = drv->remove(drv); + if (err == 0) { + mutex_lock(&drv->core->lock); + list_del(list); + mutex_unlock(&drv->core->lock); + } else + printk(KERN_ERR "%s/2: cx8802 driver remove " + "failed (%d)\n", dev->core->name, err); } - printk(KERN_INFO "%s .. Removing driver type %d\n", __FUNCTION__, h->type_id); - cx8802_unregister_driver(h); - list_del(&dev->drvlist.devlist); } /* Destroy any 8802 reference. */ diff --git a/drivers/media/video/cx88/cx88.h b/drivers/media/video/cx88/cx88.h index 2e0911bad4..eb296bdecb 100644 --- a/drivers/media/video/cx88/cx88.h +++ b/drivers/media/video/cx88/cx88.h @@ -412,7 +412,9 @@ struct cx8802_suspend_state { struct cx8802_driver { struct cx88_core *core; - struct list_head devlist; + + /* List of drivers attached to device */ + struct list_head drvlist; /* Type of driver and access required */ enum cx88_board_type type_id; @@ -478,8 +480,8 @@ struct cx8802_dev { unsigned char ts_gen_cntrl; /* List of attached drivers */ - struct cx8802_driver drvlist; - struct work_struct request_module_wk; + struct list_head drvlist; + struct work_struct request_module_wk; }; /* ----------------------------------------------------------- */ -- 2.39.5