Revert "ppdev: use new parport device model"
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 25 Mar 2016 16:02:13 +0000 (09:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 25 Mar 2016 16:02:13 +0000 (09:02 -0700)
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 <fengguang.wu@intel.com>
Reported-by: Ross Zwisler <zwisler@gmail.com>
Reported-by: Petr Mladek <pmladek@suse.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/char/ppdev.c

index d23368874710f726d485917e4d3f1ef93f3e3843..f8a483c67b07719be1f97af6bd1750bc53b04ae6 100644 (file)
@@ -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)