From 1701f680407c6cc05121566cef5293d33881fe71 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 25 Mar 2016 09:02:13 -0700 Subject: [PATCH] Revert "ppdev: use new parport device model" This reverts commit e7223f18603374d235d8bb0398532323e5f318b9. It causes problems when a ppdev tries to register before the parport driver has been registered with the device model. That will trigger the BUG_ON(!drv->bus->p); at drivers/base/driver.c:153. The call chain is kernel_init -> kernel_init_freeable -> do_one_initcall -> ppdev_init -> __parport_register_driver -> driver_register *BOOM* Reported-by: kernel test robot Reported-by: Ross Zwisler Reported-by: Petr Mladek Cc: Sudip Mukherjee Cc: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- drivers/char/ppdev.c | 25 +++++-------------------- 1 file changed, 5 insertions(+), 20 deletions(-) diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index d23368874710..f8a483c67b07 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -286,7 +286,7 @@ static int register_device(int minor, struct pp_struct *pp) struct parport *port; struct pardevice *pdev = NULL; char *name; - struct pardev_cb ppdev_cb; + int fl; name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor); if (name == NULL) @@ -299,11 +299,9 @@ static int register_device(int minor, struct pp_struct *pp) return -ENXIO; } - memset(&ppdev_cb, 0, sizeof(ppdev_cb)); - ppdev_cb.irq_func = pp_irq; - ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0; - ppdev_cb.private = pp; - pdev = parport_register_dev_model(port, name, &ppdev_cb, minor); + fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0; + pdev = parport_register_device(port, name, NULL, + NULL, pp_irq, fl, pp); parport_put_port(port); if (!pdev) { @@ -801,23 +799,10 @@ static void pp_detach(struct parport *port) device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number)); } -static int pp_probe(struct pardevice *par_dev) -{ - struct device_driver *drv = par_dev->dev.driver; - int len = strlen(drv->name); - - if (strncmp(par_dev->name, drv->name, len)) - return -ENODEV; - - return 0; -} - static struct parport_driver pp_driver = { .name = CHRDEV, - .probe = pp_probe, - .match_port = pp_attach, + .attach = pp_attach, .detach = pp_detach, - .devmodel = true, }; static int __init ppdev_init(void) -- 2.30.2