[PATCH 0/9] PNP: adjust pnp_register_driver signature

[PATCH 0/9] PNP: adjust pnp_register_driver signature

[Bjorn Helgaas]

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.

[PATCH 1/9] parport: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

parport_pc_init() does nothing with "count", so remove it.  Then nobody
uses the return value of parport_pc_find_ports(), so make it void.
Finally, update pnp_register_driver() usage.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/drivers/parport/parport_pc.c
===================================================================
--- work-mm4.orig/drivers/parport/parport_pc.c	2006-03-01 15:37:16.000000000 -0700
+++ work-mm4/drivers/parport/parport_pc.c	2006-03-02 12:41:33.000000000 -0700
@@ -3126,9 +3126,9 @@
  * autoirq is PARPORT_IRQ_NONE, PARPORT_IRQ_AUTO, or PARPORT_IRQ_PROBEONLY
  * autodma is PARPORT_DMA_NONE or PARPORT_DMA_AUTO
  */
-static int __init parport_pc_find_ports (int autoirq, int autodma)
+static void __init parport_pc_find_ports (int autoirq, int autodma)
 {
-	int count = 0, r;
+	int count = 0, err;
 
 #ifdef CONFIG_PARPORT_PC_SUPERIO
 	detect_and_report_winbond ();
@@ -3140,23 +3140,17 @@
 
 	/* PnP ports, skip detection if SuperIO already found them */
 	if (!count) {
-		r = pnp_register_driver (&parport_pc_pnp_driver);
-		if (r >= 0) {
+		err = pnp_register_driver (&parport_pc_pnp_driver);
+		if (!err)
 			pnp_registered_parport = 1;
-			count += r;
-		}
 	}
 
 	/* ISA ports and whatever (see asm/parport.h). */
-	count += parport_pc_find_nonpci_ports (autoirq, autodma);
-
-	r = pci_register_driver (&parport_pc_pci_driver);
-	if (r)
-		return r;
-	pci_registered_parport = 1;
-	count += 1;
+	parport_pc_find_nonpci_ports (autoirq, autodma);
 
-	return count;
+	err = pci_register_driver (&parport_pc_pci_driver);
+	if (!err)
+		pci_registered_parport = 1;
 }
 
 /*
@@ -3381,8 +3375,6 @@
 
 static int __init parport_pc_init(void)
 {
-	int count = 0;
-
 	if (parse_parport_params())
 		return -EINVAL;
 
@@ -3395,12 +3387,11 @@
 				break;
 			if ((io_hi[i]) == PARPORT_IOHI_AUTO)
 			       io_hi[i] = 0x400 + io[i];
-			if (parport_pc_probe_port(io[i], io_hi[i],
-						  irqval[i], dmaval[i], NULL))
-				count++;
+			parport_pc_probe_port(io[i], io_hi[i],
+						  irqval[i], dmaval[i], NULL);
 		}
 	} else
-		count += parport_pc_find_ports (irqval[0], dmaval[0]);
+		parport_pc_find_ports (irqval[0], dmaval[0]);
 
 	return 0;
 }

[PATCH 2/9] mpu401: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/sound/drivers/mpu401/mpu401.c
===================================================================
--- work-mm4.orig/sound/drivers/mpu401/mpu401.c	2006-02-01 16:24:33.000000000 -0700
+++ work-mm4/sound/drivers/mpu401/mpu401.c	2006-02-14 16:50:34.000000000 -0700
@@ -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 && enable[i]; i++) {
 		struct platform_device *device;
 #ifdef CONFIG_PNP
@@ -253,14 +254,13 @@
 			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

[PATCH 3/9] cs4236: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/sound/isa/cs423x/cs4236.c
===================================================================
--- work-mm4.orig/sound/isa/cs423x/cs4236.c	2006-02-22 09:55:41.000000000 -0700
+++ work-mm4/sound/isa/cs423x/cs4236.c	2006-02-22 10:05:14.000000000 -0700
@@ -133,6 +133,7 @@
 static int pnp_registered;
 #endif
 #endif /* CONFIG_PNP */
+static unsigned int snd_cs423x_devices;
 
 struct snd_card_cs4236 {
 	struct snd_cs4231 *chip;
@@ -564,7 +565,7 @@
 		snd_card_free(card);
 		return err;
 	}
-	
+
 	platform_set_drvdata(pdev, card);
 	return 0;
 }
@@ -650,6 +651,7 @@
 	}
 	pnp_set_drvdata(pdev, card);
 	dev++;
+	snd_cs423x_devices++;
 	return 0;
 }
 
@@ -713,6 +715,7 @@
 	}
 	pnp_set_card_drvdata(pcard, card);
 	dev++;
+	snd_cs423x_devices++;
 	return 0;
 }
 
@@ -721,7 +724,7 @@
 	snd_card_free(pnp_get_card_drvdata(pcard));
 	pnp_set_card_drvdata(pcard, NULL);
 }
-                        
+
 #ifdef CONFIG_PM
 static int snd_cs423x_pnpc_suspend(struct pnp_card_link *pcard, pm_message_t state)
 {
@@ -766,7 +769,7 @@
 
 static int __init alsa_card_cs423x_init(void)
 {
-	int i, err, cards = 0;
+	int i, err;
 
 	if ((err = platform_driver_register(&cs423x_nonpnp_driver)) < 0)
 		return err;
@@ -782,24 +785,20 @@
 			goto errout;
 		}
 		platform_devices[i] = device;
-		cards++;
+		snd_cs423x_devices++;
 	}
 #ifdef CONFIG_PNP
 #ifdef CS4232
-	i = pnp_register_driver(&cs4232_pnp_driver);
-	if (i >= 0) {
+	err = pnp_register_driver(&cs4232_pnp_driver);
+	if (!err)
 		pnp_registered = 1;
-		cards += i;
-	}
 #endif
-	i = pnp_register_card_driver(&cs423x_pnpc_driver);
-	if (i >= 0) {
+	err = pnp_register_card_driver(&cs423x_pnpc_driver);
+	if (!err)
 		pnpc_registered = 1;
-		cards += i;
-	}
 #endif /* CONFIG_PNP */
 
-	if (!cards) {
+	if (!snd_cs423x_devices) {
 #ifdef MODULE
 		printk(KERN_ERR IDENT " soundcard not found or device busy\n");
 #endif

[PATCH 4/9] opl3sa2: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/sound/isa/opl3sa2.c
===================================================================
--- work-mm4.orig/sound/isa/opl3sa2.c	2006-02-01 16:24:54.000000000 -0700
+++ work-mm4/sound/isa/opl3sa2.c	2006-02-15 10:11:17.000000000 -0700
@@ -95,6 +95,7 @@
 static int pnp_registered;
 static int pnpc_registered;
 #endif
+static unsigned int snd_opl3sa2_devices;
 
 /* control ports */
 #define OPL3SA2_PM_CTRL		0x01
@@ -760,6 +761,7 @@
 	}
 	pnp_set_drvdata(pdev, card);
 	dev++;
+	snd_opl3sa2_devices++;
 	return 0;
 }
 
@@ -826,6 +828,7 @@
 	}
 	pnp_set_card_drvdata(pcard, card);
 	dev++;
+	snd_opl3sa2_devices++;
 	return 0;
 }
 
@@ -944,7 +947,7 @@
 
 static int __init alsa_card_opl3sa2_init(void)
 {
-	int i, err, cards = 0;
+	int i, err;
 
 	if ((err = platform_driver_register(&snd_opl3sa2_nonpnp_driver)) < 0)
 		return err;
@@ -962,23 +965,19 @@
 			goto errout;
 		}
 		platform_devices[i] = device;
-		cards++;
+		snd_opl3sa2_devices++;
 	}
 
 #ifdef CONFIG_PNP
 	err = pnp_register_driver(&opl3sa2_pnp_driver);
-	if (err >= 0) {
+	if (!err)
 		pnp_registered = 1;
-		cards += err;
-	}
 	err = pnp_register_card_driver(&opl3sa2_pnpc_driver);
-	if (err >= 0) {
+	if (!err)
 		pnpc_registered = 1;
-		cards += err;
-	}
 #endif
 
-	if (!cards) {
+	if (!snd_opl3sa2_devices) {
 #ifdef MODULE
 		snd_printk(KERN_ERR "Yamaha OPL3-SA soundcard not found or device busy\n");
 #endif

[PATCH 5/9] ns558: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/drivers/input/gameport/ns558.c
===================================================================
--- work-mm4.orig/drivers/input/gameport/ns558.c	2006-03-02 12:40:45.000000000 -0700
+++ work-mm4/drivers/input/gameport/ns558.c	2006-03-02 12:43:58.000000000 -0700
@@ -256,9 +256,10 @@
 
 static int __init ns558_init(void)
 {
-	int i = 0;
+	int i = 0, err;
 
-	if (pnp_register_driver(&ns558_pnp_driver) >= 0)
+	err = pnp_register_driver(&ns558_pnp_driver);
+	if (!err)
 		pnp_registered = 1;
 
 /*

[PATCH 6/9] i8042: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/drivers/input/serio/i8042-x86ia64io.h
===================================================================
--- work-mm4.orig/drivers/input/serio/i8042-x86ia64io.h	2006-03-02 12:40:45.000000000 -0700
+++ work-mm4/drivers/input/serio/i8042-x86ia64io.h	2006-03-02 12:45:21.000000000 -0700
@@ -192,7 +192,9 @@
 #include <linux/pnp.h>
 
 static int i8042_pnp_kbd_registered;
+static unsigned int i8042_pnp_kbd_devices;
 static int i8042_pnp_aux_registered;
+static unsigned int i8042_pnp_aux_devices;
 
 static int i8042_pnp_command_reg;
 static int i8042_pnp_data_reg;
@@ -219,6 +221,7 @@
 		strncat(i8042_pnp_kbd_name, pnp_dev_name(dev), sizeof(i8042_pnp_kbd_name));
 	}
 
+	i8042_pnp_kbd_devices++;
 	return 0;
 }
 
@@ -239,6 +242,7 @@
 		strncat(i8042_pnp_aux_name, pnp_dev_name(dev), sizeof(i8042_pnp_aux_name));
 	}
 
+	i8042_pnp_aux_devices++;
 	return 0;
 }
 
@@ -287,21 +291,23 @@
 
 static int __init i8042_pnp_init(void)
 {
-	int result_kbd = 0, result_aux = 0;
 	char kbd_irq_str[4] = { 0 }, aux_irq_str[4] = { 0 };
+	int err;
 
 	if (i8042_nopnp) {
 		printk(KERN_INFO "i8042: PNP detection disabled\n");
 		return 0;
 	}
 
-	if ((result_kbd = pnp_register_driver(&i8042_pnp_kbd_driver)) >= 0)
+	err = pnp_register_driver(&i8042_pnp_kbd_driver);
+	if (!err)
 		i8042_pnp_kbd_registered = 1;
 
-	if ((result_aux = pnp_register_driver(&i8042_pnp_aux_driver)) >= 0)
+	err = pnp_register_driver(&i8042_pnp_aux_driver);
+	if (!err)
 		i8042_pnp_aux_registered = 1;
 
-	if (result_kbd <= 0 && result_aux <= 0) {
+	if (!i8042_pnp_kbd_devices && !i8042_pnp_aux_devices) {
 		i8042_pnp_exit();
 #if defined(__ia64__)
 		return -ENODEV;
@@ -311,24 +317,24 @@
 #endif
 	}
 
-	if (result_kbd > 0)
+	if (i8042_pnp_kbd_devices)
 		snprintf(kbd_irq_str, sizeof(kbd_irq_str),
 			"%d", i8042_pnp_kbd_irq);
-	if (result_aux > 0)
+	if (i8042_pnp_aux_devices)
 		snprintf(aux_irq_str, sizeof(aux_irq_str),
 			"%d", i8042_pnp_aux_irq);
 
 	printk(KERN_INFO "PNP: PS/2 Controller [%s%s%s] at %#x,%#x irq %s%s%s\n",
-		i8042_pnp_kbd_name, (result_kbd > 0 && result_aux > 0) ? "," : "",
+		i8042_pnp_kbd_name, (i8042_pnp_kbd_devices && i8042_pnp_aux_devices) ? "," : "",
 		i8042_pnp_aux_name,
 		i8042_pnp_data_reg, i8042_pnp_command_reg,
-		kbd_irq_str, (result_kbd > 0 && result_aux > 0) ? "," : "",
+		kbd_irq_str, (i8042_pnp_kbd_devices && i8042_pnp_aux_devices) ? "," : "",
 		aux_irq_str);
 
 #if defined(__ia64__)
-	if (result_kbd <= 0)
+	if (!i8042_pnp_kbd_devices)
 		i8042_nokbd = 1;
-	if (result_aux <= 0)
+	if (!i8042_pnp_aux_devices)
 		i8042_noaux = 1;
 #endif
 

[PATCH 7/9] IRDA: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/drivers/net/irda/nsc-ircc.c
===================================================================
--- work-mm4.orig/drivers/net/irda/nsc-ircc.c	2006-02-22 09:55:50.000000000 -0700
+++ work-mm4/drivers/net/irda/nsc-ircc.c	2006-02-22 10:06:53.000000000 -0700
@@ -207,7 +207,7 @@
  	/* Register with PnP subsystem to detect disable ports */
 	ret = pnp_register_driver(&nsc_ircc_pnp_driver);
 
- 	if (ret >= 0)
+ 	if (!ret)
  		pnp_registered = 1;
 
 	ret = -ENODEV;

[PATCH 8/9] cs4232: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove the assumption that pnp_register_driver() returns the number of
devices claimed.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/sound/oss/cs4232.c
===================================================================
--- work-mm4.orig/sound/oss/cs4232.c	2006-01-02 20:21:10.000000000 -0700
+++ work-mm4/sound/oss/cs4232.c	2006-02-15 15:44:34.000000000 -0700
@@ -360,6 +360,8 @@
 static int __initdata synthirq	= -1;
 static int __initdata isapnp	= 1;
 
+static unsigned int cs4232_devices;
+
 MODULE_DESCRIPTION("CS4232 based soundcard driver"); 
 MODULE_AUTHOR("Hannu Savolainen, Paul Barton-Davis"); 
 MODULE_LICENSE("GPL");
@@ -421,6 +423,7 @@
 		return -ENODEV;
 	}
 	pnp_set_drvdata(dev,isapnpcfg);
+	cs4232_devices++;
 	return 0;
 }
 
@@ -455,10 +458,11 @@
 #endif
 	cfg.irq = -1;
 
-	if (isapnp &&
-	    (pnp_register_driver(&cs4232_driver) > 0)
-	)
-		return 0;
+	if (isapnp) {
+		pnp_register_driver(&cs4232_driver);
+		if (cs4232_devices)
+			return 0;
+	}
 
 	if(io==-1||irq==-1||dma==-1)
 	{
@@ -503,7 +507,8 @@
 	int ints[7];
 
 	/* If we have isapnp cards, no need for options */
-	if (pnp_register_driver(&cs4232_driver) > 0)
+	pnp_register_driver(&cs4232_driver);
+	if (cs4232_devices)
 		return 1;
 	
 	str = get_options(str, ARRAY_SIZE(ints), ints);

[PATCH 9/9] PNP: adjust pnp_register_driver signature

[Bjorn Helgaas]

Remove 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.

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().

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work-mm4/drivers/pnp/driver.c
===================================================================
--- work-mm4.orig/drivers/pnp/driver.c	2006-03-02 12:40:45.000000000 -0700
+++ work-mm4/drivers/pnp/driver.c	2006-03-02 12:46:49.000000000 -0700
@@ -201,31 +201,14 @@
 	.resume = pnp_bus_resume,
 };
 
-
-static int count_devices(struct device * dev, void * c)
-{
-	int * count = c;
-	(*count)++;
-	return 0;
-}
-
 int pnp_register_driver(struct pnp_driver *drv)
 {
-	int count;
-
 	pnp_dbg("the driver '%s' has been registered", drv->name);
 
 	drv->driver.name = drv->name;
 	drv->driver.bus = &pnp_bus_type;
 
-	count = driver_register(&drv->driver);
-
-	/* get the number of initial matches */
-	if (count >= 0){
-		count = 0;
-		driver_for_each_device(&drv->driver, NULL, &count, count_devices);
-	}
-	return count;
+	return driver_register(&drv->driver);
 }
 
 void pnp_unregister_driver(struct pnp_driver *drv)
Index: work-mm4/drivers/pnp/card.c
===================================================================
--- work-mm4.orig/drivers/pnp/card.c	2006-03-02 12:40:45.000000000 -0700
+++ work-mm4/drivers/pnp/card.c	2006-03-02 12:46:49.000000000 -0700
@@ -47,7 +47,7 @@
 {
 	dev->card_link = NULL;
 }
- 
+
 static void card_remove_first(struct pnp_dev * dev)
 {
 	struct pnp_card_driver * drv = to_pnp_card_driver(dev->driver);
@@ -373,7 +373,7 @@
 
 int pnp_register_card_driver(struct pnp_card_driver * drv)
 {
-	int count;
+	int error;
 	struct list_head *pos, *temp;
 
 	drv->link.name = drv->name;
@@ -384,21 +384,19 @@
 	drv->link.suspend = drv->suspend ? card_suspend : NULL;
 	drv->link.resume = drv->resume ? card_resume : NULL;
 
-	count = pnp_register_driver(&drv->link);
-	if (count < 0)
-		return count;
+	error = pnp_register_driver(&drv->link);
+	if (error < 0)
+		return error;
 
 	spin_lock(&pnp_lock);
 	list_add_tail(&drv->global_list, &pnp_card_drivers);
 	spin_unlock(&pnp_lock);
 
-	count = 0;
-
 	list_for_each_safe(pos,temp,&pnp_cards){
 		struct pnp_card *card = list_entry(pos, struct pnp_card, global_list);
-		count += card_probe(card,drv);
+		card_probe(card,drv);
 	}
-	return count;
+	return 0;
 }
 
 /**
Index: work-mm4/Documentation/pnp.txt
===================================================================
--- work-mm4.orig/Documentation/pnp.txt	2006-03-02 12:40:45.000000000 -0700
+++ work-mm4/Documentation/pnp.txt	2006-03-02 12:48:01.000000000 -0700
@@ -115,6 +115,9 @@
 pnp_register_driver
 - adds a PnP driver to the Plug and Play Layer
 - this includes driver model integration
+- returns zero for success or a negative error number for failure; count
+  calls to the .add() method if you need to know how many devices bind to
+  the driver
 
 pnp_unregister_driver
 - removes a PnP driver from the Plug and Play Layer

Re: [PATCH 5/9] ns558: adjust pnp_register_driver signature

[Vojtech Pavlik]

On Thu, Mar 02, 2006 at 04:09:37PM -0700, Bjorn Helgaas wrote:
> Remove the assumption that pnp_register_driver() returns the number of
> devices claimed.
> 
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Wouldn't a diff like

--- a/drivers/input/gameport/ns558.c	2006-03-02 12:40:45.000000000 -0700
+++ b/drivers/input/gameport/ns558.c	2006-03-02 12:43:58.000000000 -0700
@@ -258,7 +256,7 @@
 {
 	int i = 0;
 
-	if (pnp_register_driver(&ns558_pnp_driver) >= 0)
+	if (!pnp_register_driver(&ns558_pnp_driver))
 		pnp_registered = 1;
  
  /*

be enough? The err variable isn't used anywhere else.

> Index: work-mm4/drivers/input/gameport/ns558.c
> ===================================================================
> --- work-mm4.orig/drivers/input/gameport/ns558.c	2006-03-02 12:40:45.000000000 -0700
> +++ work-mm4/drivers/input/gameport/ns558.c	2006-03-02 12:43:58.000000000 -0700
> @@ -256,9 +256,10 @@
>  
>  static int __init ns558_init(void)
>  {
> -	int i = 0;
> +	int i = 0, err;
>  
> -	if (pnp_register_driver(&ns558_pnp_driver) >= 0)
> +	err = pnp_register_driver(&ns558_pnp_driver);
> +	if (!err)
>  		pnp_registered = 1;
>  
>  /*
> 
> 

-- 
Vojtech Pavlik
Director SuSE Labs

Re: [PATCH 5/9] ns558: adjust pnp_register_driver signature

[Bjorn Helgaas]

On Friday 03 March 2006 05:55, Vojtech Pavlik wrote:
> On Thu, Mar 02, 2006 at 04:09:37PM -0700, Bjorn Helgaas wrote:
> > Remove the assumption that pnp_register_driver() returns the number of
> > devices claimed.
> > 
> > Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
> 
> Wouldn't a diff like
> 
> --- a/drivers/input/gameport/ns558.c	2006-03-02 12:40:45.000000000 -0700
> +++ b/drivers/input/gameport/ns558.c	2006-03-02 12:43:58.000000000 -0700
> @@ -258,7 +256,7 @@
>  {
>  	int i = 0;
>  
> -	if (pnp_register_driver(&ns558_pnp_driver) >= 0)
> +	if (!pnp_register_driver(&ns558_pnp_driver))
>  		pnp_registered = 1;
>   
>   /*
> 
> be enough? The err variable isn't used anywhere else.

Yup, that'd be fine, and in fact my first version of the patch
did just that.  I introduced "err" because most of the other
drivers I had to touch used "err," and it seemed a bit clearer to me
because it gives an extra hint that pnp_register_driver() returns
only an error code.

But I don't care either way, so say the word, and I'll send
Andrew your patch to replace mine.

Bjorn

> > Index: work-mm4/drivers/input/gameport/ns558.c
> > ===================================================================
> > --- work-mm4.orig/drivers/input/gameport/ns558.c	2006-03-02 12:40:45.000000000 -0700
> > +++ work-mm4/drivers/input/gameport/ns558.c	2006-03-02 12:43:58.000000000 -0700
> > @@ -256,9 +256,10 @@
> >  
> >  static int __init ns558_init(void)
> >  {
> > -	int i = 0;
> > +	int i = 0, err;
> >  
> > -	if (pnp_register_driver(&ns558_pnp_driver) >= 0)
> > +	err = pnp_register_driver(&ns558_pnp_driver);
> > +	if (!err)
> >  		pnp_registered = 1;
> >  
> >  /*
> > 
> > 
> 

Re: [PATCH 6/9] i8042: adjust pnp_register_driver signature

[Dmitry Torokhov]

On Thursday 02 March 2006 18:09, Bjorn Helgaas wrote:
> Remove the assumption that pnp_register_driver() returns the number of
> devices claimed.
>

Applied, thank you Bjorn.

-- 
Dmitry

Re: [PATCH 0/9] PNP: adjust pnp_register_driver signature

[Adam Belay]

On Thu, Mar 02, 2006 at 04:01:27PM -0700, Bjorn Helgaas wrote:
> 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.

Andrew, I'd appreciate if you add this to mainline when it's convenient to
make non-critical changes.

Thanks,
Adam