[PATCH] pnp: mpu401: adjust pnp_register_driver signature
This series of patches removes the assumption that pnp_register_driver()
returns the number of devices claimed. Returning the count is unreliable
because devices may be hot-plugged in the future. (Many devices don't support
hot-plug, of course, but PNP in general does.)
This changes the convention to "zero for success, or a negative error value,"
which matches pci_register_driver(), acpi_bus_register_driver(), and
platform_driver_register().
If drivers need to know the number of devices, they can count calls to their
.probe() methods.
This patch:
Remove the assumption that pnp_register_driver() returns the number of devices
claimed.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/sound/drivers/mpu401/mpu401.c b/sound/drivers/mpu401/mpu401.c
index 9d10d79..9ea3059 100644
--- a/sound/drivers/mpu401/mpu401.c
+++ b/sound/drivers/mpu401/mpu401.c
@@ -59,7 +59,8 @@
MODULE_PARM_DESC(irq, "IRQ # for MPU-401 device.");
static struct platform_device *platform_devices[SNDRV_CARDS];
-static int pnp_registered = 0;
+static int pnp_registered;
+static unsigned int snd_mpu401_devices;
static int snd_mpu401_create(int dev, struct snd_card **rcard)
{
@@ -197,6 +198,7 @@
}
snd_card_set_dev(card, &pnp_dev->dev);
pnp_set_drvdata(pnp_dev, card);
+ snd_mpu401_devices++;
++dev;
return 0;
}
@@ -234,12 +236,11 @@
static int __init alsa_card_mpu401_init(void)
{
- int i, err, devices;
+ int i, err;
if ((err = platform_driver_register(&snd_mpu401_driver)) < 0)
return err;
- devices = 0;
for (i = 0; i < SNDRV_CARDS; i++) {
struct platform_device *device;
if (! enable[i])
@@ -255,14 +256,13 @@
goto errout;
}
platform_devices[i] = device;
- devices++;
+ snd_mpu401_devices++;
}
- if ((err = pnp_register_driver(&snd_mpu401_pnp_driver)) >= 0) {
+ err = pnp_register_driver(&snd_mpu401_pnp_driver);
+ if (!err)
pnp_registered = 1;
- devices += err;
- }
- if (!devices) {
+ if (!snd_mpu401_devices) {
#ifdef MODULE
printk(KERN_ERR "MPU-401 device not found or device busy\n");
#endif