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Revert "ppdev: use new parport device model" 

This reverts commit e7223f1860.

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>
This commit is contained in:
Linus Torvalds 2016-03-25 09:02:13 -07:00
parent 3b3b3bd977
commit 1701f68040
1 changed files with 5 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
drivers/char/ppdev.c
View 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)