[PATCH] network driver updates

[PATCH] network driver updates

[Manfred Spraul]

[-- Attachment #1: Type: text/plain, Size: 507 bytes --]

I found 2 bugs in several network drivers:

* dev->mem_start: NULL means "not command line configuration" 0xffffffff
means "default".
several drivers only check for NULL, not for 0xffffffff.

* incorrect bounds checks for phy_idx: 2 entries in the structure, but
up to 4 are initialized.

* something is wrong in the vortex initialization: I don't have such a
card, but the driver didn't return an error message on insmod. I'm not
sure if
my fix is correct.

Patch attached, against 2.4.1-ac12.

--
	Manfred

[-- Attachment #2: patch-donald --]
[-- Type: text/plain, Size: 10038 bytes --]

diff -ur 2.4/drivers/net/3c59x.c build-2.4/drivers/net/3c59x.c
--- 2.4/drivers/net/3c59x.c	Wed Feb 14 10:50:50 2001
+++ build-2.4/drivers/net/3c59x.c	Wed Feb 14 12:32:56 2001
@@ -967,7 +967,7 @@
 		pdev->driver_data = dev;
 
 	/* The lower four bits are the media type. */
-	if (dev->mem_start) {
+	if (dev->mem_start && dev->mem_start != 0xffffffff) {
 		/*
 		 * AKPM: ewww..  The 'options' param is passed in as the third arg to the
 		 * LILO 'ether=' argument for non-modular use
@@ -2661,9 +2661,12 @@
 	
 	rc = pci_module_init(&vortex_driver);
 	if (rc < 0) {
-		rc = vortex_eisa_init();
-		if (rc > 0)
+		int rc2;
+		rc2 = vortex_eisa_init();
+		if (rc2 > 0) {
 			vortex_have_eisa = 1;
+			rc = 0;
+		}
 	} else {
 		vortex_have_pci = 1;
 	}
diff -ur 2.4/drivers/net/eepro100.c build-2.4/drivers/net/eepro100.c
--- 2.4/drivers/net/eepro100.c	Wed Feb 14 10:50:54 2001
+++ build-2.4/drivers/net/eepro100.c	Wed Feb 14 11:23:22 2001
@@ -643,7 +643,7 @@
 		return -1;
 	}
 
-	if (dev->mem_start > 0)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 	else if (card_idx >= 0  &&  options[card_idx] >= 0)
 		option = options[card_idx];
diff -ur 2.4/drivers/net/epic100.c build-2.4/drivers/net/epic100.c
--- 2.4/drivers/net/epic100.c	Wed Feb 14 10:50:54 2001
+++ build-2.4/drivers/net/epic100.c	Wed Feb 14 11:17:37 2001
@@ -412,7 +412,7 @@
 	ep->rx_ring = (struct epic_rx_desc *)ring_space;
 	ep->rx_ring_dma = ring_dma;
 
-	if (dev->mem_start) {
+	if (dev->mem_start && dev->mem_start != 0xffffffff) {
 		option = dev->mem_start;
 		duplex = (dev->mem_start & 16) ? 1 : 0;
 	} else if (card_idx >= 0  &&  card_idx < MAX_UNITS) {
diff -ur 2.4/drivers/net/hamachi.c build-2.4/drivers/net/hamachi.c
--- 2.4/drivers/net/hamachi.c	Wed Feb 14 10:50:54 2001
+++ build-2.4/drivers/net/hamachi.c	Wed Feb 14 11:26:54 2001
@@ -477,6 +477,7 @@
 };
 
 #define PRIV_ALIGN   15    				/* Required alignment mask */
+#define MII_CNT		4
 struct hamachi_private {
 	/* Descriptor rings first for alignment.  Tx requires a second descriptor
 	   for status. */
@@ -503,7 +504,7 @@
 	/* MII transceiver section. */
 	int mii_cnt;								/* MII device addresses. */
 	u16 advertising;							/* NWay media advertisement */
-	unsigned char phys[2];					/* MII device addresses. */
+	unsigned char phys[MII_CNT];		/* MII device addresses, only first one used. */
 	u_int32_t rx_int_var, tx_int_var;	/* interrupt control variables */
 	u_int32_t option;							/* Hold on to a copy of the options */
 	u_int8_t pad[16];							/* Used for 32-byte alignment */
@@ -621,7 +622,7 @@
 
 	/* Check for options being passed in */
 	option = card_idx < MAX_UNITS ? options[card_idx] : 0;
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* If the bus size is misidentified, do the following. */
@@ -705,7 +706,7 @@
 
 	if (chip_tbl[hmp->chip_id].flags & CanHaveMII) {
 		int phy, phy_idx = 0;
-		for (phy = 0; phy < 32 && phy_idx < 4; phy++) {
+		for (phy = 0; phy < 32 && phy_idx < MII_CNT; phy++) {
 			int mii_status = mdio_read(ioaddr, phy, 1);
 			if (mii_status != 0xffff  &&
 				mii_status != 0x0000) {
diff -ur 2.4/drivers/net/natsemi.c build-2.4/drivers/net/natsemi.c
--- 2.4/drivers/net/natsemi.c	Wed Feb 14 10:50:56 2001
+++ build-2.4/drivers/net/natsemi.c	Wed Feb 14 11:17:52 2001
@@ -446,7 +446,7 @@
 	np->iosize = iosize;
 	spin_lock_init(&np->lock);
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
diff -ur 2.4/drivers/net/starfire.c build-2.4/drivers/net/starfire.c
--- 2.4/drivers/net/starfire.c	Wed Feb 14 10:51:00 2001
+++ build-2.4/drivers/net/starfire.c	Wed Feb 14 11:26:07 2001
@@ -329,6 +329,7 @@
 	dma_addr_t mapping;
 };
 
+#define MII_CNT		4
 struct netdev_private {
 	/* Descriptor rings first for alignment. */
 	struct starfire_rx_desc *rx_ring;
@@ -365,7 +366,7 @@
 	/* MII transceiver section. */
 	int mii_cnt;						/* MII device addresses. */
 	u16 advertising;					/* NWay media advertisement */
-	unsigned char phys[2];				/* MII device addresses. */
+	unsigned char phys[MII_CNT];		/* MII device addresses, only first one used. */
 };
 
 static int  mdio_read(struct net_device *dev, int phy_id, int location);
@@ -467,7 +468,7 @@
 	np->pci_dev = pdev;
 	drv_flags = netdrv_tbl[chip_idx].drv_flags;
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
@@ -499,7 +500,7 @@
 
 	if (drv_flags & CanHaveMII) {
 		int phy, phy_idx = 0;
-		for (phy = 0; phy < 32 && phy_idx < 4; phy++) {
+		for (phy = 0; phy < 32 && phy_idx < MII_CNT; phy++) {
 			int mii_status = mdio_read(dev, phy, 1);
 			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
 				np->phys[phy_idx++] = phy;
diff -ur 2.4/drivers/net/sundance.c build-2.4/drivers/net/sundance.c
--- 2.4/drivers/net/sundance.c	Wed Feb 14 10:51:00 2001
+++ build-2.4/drivers/net/sundance.c	Wed Feb 14 11:25:14 2001
@@ -314,6 +314,7 @@
 #define PRIV_ALIGN	15 	/* Required alignment mask */
 /* Use  __attribute__((aligned (L1_CACHE_BYTES)))  to maintain alignment
    within the structure. */
+#define MII_CNT		4
 struct netdev_private {
 	/* Descriptor rings first for alignment. */
 	struct netdev_desc rx_ring[RX_RING_SIZE];
@@ -346,7 +347,7 @@
 	/* MII transceiver section. */
 	int mii_cnt;						/* MII device addresses. */
 	u16 advertising;					/* NWay media advertisement */
-	unsigned char phys[2];				/* MII device addresses. */
+	unsigned char phys[MII_CNT];		/* MII device addresses, only first one used. */
 };
 
 /* The station address location in the EEPROM. */
@@ -425,7 +426,7 @@
 	np->drv_flags = pci_id_tbl[chip_idx].drv_flags;
 	spin_lock_init(&np->lock);
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
@@ -458,7 +459,7 @@
 	if (1) {
 		int phy, phy_idx = 0;
 		np->phys[0] = 1;		/* Default setting */
-		for (phy = 0; phy < 32 && phy_idx < 4; phy++) {
+		for (phy = 0; phy < 32 && phy_idx < MII_CNT; phy++) {
 			int mii_status = mdio_read(dev, phy, 1);
 			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
 				np->phys[phy_idx++] = phy;
diff -ur 2.4/drivers/net/tulip/tulip_core.c build-2.4/drivers/net/tulip/tulip_core.c
--- 2.4/drivers/net/tulip/tulip_core.c	Wed Feb 14 10:51:02 2001
+++ build-2.4/drivers/net/tulip/tulip_core.c	Wed Feb 14 12:35:12 2001
@@ -1294,9 +1294,11 @@
 		if (mtu[board_idx] > 0)
 			dev->mtu = mtu[board_idx];
 	}
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		tp->default_port = dev->mem_start;
 	if (tp->default_port) {
+		printk("%s: forced to media type %s (%d).\n",
+			dev->name, medianame[tp->default_port], tp->default_port);
 		tp->medialock = 1;
 		if (tulip_media_cap[tp->default_port] & MediaAlwaysFD)
 			tp->full_duplex = 1;
diff -ur 2.4/drivers/net/via-rhine.c build-2.4/drivers/net/via-rhine.c
--- 2.4/drivers/net/via-rhine.c	Wed Feb 14 10:51:02 2001
+++ build-2.4/drivers/net/via-rhine.c	Wed Feb 14 11:18:15 2001
@@ -571,7 +571,7 @@
 	np->drv_flags = via_rhine_chip_info[chip_id].drv_flags;
 	np->pdev = pdev;
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
diff -ur 2.4/drivers/net/winbond-840.c build-2.4/drivers/net/winbond-840.c
--- 2.4/drivers/net/winbond-840.c	Wed Feb 14 10:51:04 2001
+++ build-2.4/drivers/net/winbond-840.c	Wed Feb 14 11:21:08 2001
@@ -313,6 +313,7 @@
 };
 
 #define PRIV_ALIGN	15 	/* Required alignment mask */
+#define MII_CNT		4
 struct netdev_private {
 	struct w840_rx_desc *rx_ring;
 	dma_addr_t	rx_addr[RX_RING_SIZE];
@@ -344,7 +345,7 @@
 	/* MII transceiver section. */
 	int mii_cnt;						/* MII device addresses. */
 	u16 advertising;					/* NWay media advertisement */
-	unsigned char phys[2];				/* MII device addresses. */
+	unsigned char phys[MII_CNT];		/* MII device addresses, but only the first is used */
 };
 
 static int  eeprom_read(long ioaddr, int location);
@@ -436,7 +437,7 @@
 	
 	pdev->driver_data = dev;
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
@@ -465,7 +466,7 @@
 
 	if (np->drv_flags & CanHaveMII) {
 		int phy, phy_idx = 0;
-		for (phy = 1; phy < 32 && phy_idx < 4; phy++) {
+		for (phy = 1; phy < 32 && phy_idx < MII_CNT; phy++) {
 			int mii_status = mdio_read(dev, phy, 1);
 			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
 				np->phys[phy_idx++] = phy;
diff -ur 2.4/drivers/net/yellowfin.c build-2.4/drivers/net/yellowfin.c
--- 2.4/drivers/net/yellowfin.c	Wed Feb 14 10:51:04 2001
+++ build-2.4/drivers/net/yellowfin.c	Wed Feb 14 11:22:47 2001
@@ -328,6 +328,7 @@
 	IntrEarlyRx=0x100, IntrWakeup=0x200, };
 
 #define PRIV_ALIGN	31 	/* Required alignment mask */
+#define MII_CNT		4
 struct yellowfin_private {
 	/* Descriptor rings first for alignment.
 	   Tx requires a second descriptor for status. */
@@ -357,7 +358,7 @@
 	/* MII transceiver section. */
 	int mii_cnt;						/* MII device addresses. */
 	u16 advertising;					/* NWay media advertisement */
-	unsigned char phys[2];				/* MII device addresses. */
+	unsigned char phys[MII_CNT];		/* MII device addresses, only first one used */
 	spinlock_t lock;
 };
 
@@ -453,7 +454,7 @@
 	np->chip_id = chip_idx;
 	np->drv_flags = drv_flags;
 
-	if (dev->mem_start)
+	if (dev->mem_start && dev->mem_start != 0xffffffff)
 		option = dev->mem_start;
 
 	/* The lower four bits are the media type. */
@@ -485,7 +486,7 @@
 
 	if (np->drv_flags & HasMII) {
 		int phy, phy_idx = 0;
-		for (phy = 0; phy < 32 && phy_idx < 4; phy++) {
+		for (phy = 0; phy < 32 && phy_idx < MII_CNT; phy++) {
 			int mii_status = mdio_read(ioaddr, phy, 1);
 			if (mii_status != 0xffff  &&  mii_status != 0x0000) {
 				np->phys[phy_idx++] = phy;

Re: [PATCH] network driver updates

[Jeff Garzik]

On Wed, 14 Feb 2001, Manfred Spraul wrote:
> * dev->mem_start: NULL means "not command line configuration" 0xffffffff
> means "default".
> several drivers only check for NULL, not for 0xffffffff.

netdev->mem_start is unsigned long... Should the test be for ~0 instead?
The value 0xFFFFFFFF seems wrong for 64-bit machines.

	Jeff

Re: [PATCH] network driver updates

[Arnaldo Carvalho de Melo]

Em Wed, Feb 14, 2001 at 05:54:34AM -0600, Jeff Garzik escreveu:
> On Wed, 14 Feb 2001, Manfred Spraul wrote:
> > * dev->mem_start: NULL means "not command line configuration" 0xffffffff
> > means "default".
> > several drivers only check for NULL, not for 0xffffffff.
> 
> netdev->mem_start is unsigned long... Should the test be for ~0 instead?
> The value 0xFFFFFFFF seems wrong for 64-bit machines.

I've added this to the Janitor's TODO List.

http://bazar.conectiva.com.br/~acme/TODO

- Arnaldo

Re: [PATCH] network driver updates

[Jeff Garzik]

On Wed, 14 Feb 2001, Manfred Spraul wrote:
> * something is wrong in the vortex initialization: I don't have such a
> card, but the driver didn't return an error message on insmod. I'm not
> sure if
> my fix is correct.

> @@ -2661,9 +2661,12 @@
>  
>         rc = pci_module_init(&vortex_driver);
>         if (rc < 0) {
> -               rc = vortex_eisa_init();
> -               if (rc > 0)
> +               int rc2;
> +               rc2 = vortex_eisa_init();
> +               if (rc2 > 0) {
>                         vortex_have_eisa = 1;
> +                       rc = 0;
> +               }
>         } else {
>                 vortex_have_pci = 1;
>         }

IMHO vortex should be trying to initialize EISA regardless of the
results of the PCI probe... Andrew?

	Jeff

Re: [PATCH] network driver updates

[Andrew Morton]

Manfred Spraul wrote:
> 
> I found 2 bugs in several network drivers:
> 
> * dev->mem_start: NULL means "not command line configuration" 0xffffffff
> means "default".
> several drivers only check for NULL, not for 0xffffffff.

I think that's worth another "ewww...", don't you?

> * something is wrong in the vortex initialization: I don't have such a
> card, but the driver didn't return an error message on insmod. I'm not
> sure if my fix is correct.

That was intentional - dhinds suggested that if the hardware
isn't present the driver should float about in memory anyway.
That is the current behaviour of 3c575_cb.c  I forget the
rationale for this.  Perhaps David can remind me?

There are a fair few pending 3c59x updates wrt Linus'
tree - small stuff.  Most are in the zerocopy patch,
and there's a delta on top of that here.


Jeff Garzik wrote:
> 
> 
> IMHO vortex should be trying to initialize EISA regardless of the
> results of the PCI probe... Andrew?

I guess so.  Testing is hard - EISA vorticies are hen's teeth.  I've
heard from only two people who have such hardware in a year.

I've made the below change.  Pending enlightenment from
DavidH and some testing from my sole EISA Vortex person,
I'll flush this stuff out to DavidM.  Thanks.



--- drivers/net/3c59x.c	2001/02/14 11:51:43	1.41
+++ drivers/net/3c59x.c	2001/02/14 13:23:49
@@ -866,8 +866,7 @@
 		}
 
 		rc = vortex_probe1(NULL, ioaddr, inw(ioaddr + 0xC88) >> 12,
-				   EISA_TBL_OFFSET,
-				   vortex_cards_found);
+				   EISA_TBL_OFFSET, vortex_cards_found);
 		if (rc == 0)
 			vortex_cards_found++;
 		else
@@ -1005,7 +1004,7 @@
 		pdev->driver_data = dev;
 
 	/* The lower four bits are the media type. */
-	if (dev->mem_start) {
+	if (dev->mem_start && dev->mem_start != ~0UL) {
 		/*
 		 * AKPM: ewww..  The 'options' param is passed in as the third arg to the
 		 * LILO 'ether=' argument for non-modular use
@@ -2794,18 +2793,17 @@
 
 static int __init vortex_init (void)
 {
-	int rc;
-	
-	rc = pci_module_init(&vortex_driver);
-	if (rc < 0) {
-		rc = vortex_eisa_init();
-		if (rc > 0)
-			vortex_have_eisa = 1;
-	} else {
+	int pci_rc, eisa_rc;
+
+	pci_rc = pci_module_init(&vortex_driver);
+	eisa_rc = vortex_eisa_init();
+
+	if (pci_rc == 0)
 		vortex_have_pci = 1;
-	}
+	if (eisa_rc > 0)
+		vortex_have_eisa = 1;
 
-	return rc;
+	return (vortex_have_pci + vortex_have_eisa) ? 0 : -ENODEV;
 }

Re: [PATCH] network driver updates

[David Hinds]

On Thu, Feb 15, 2001 at 12:33:43AM +1100, Andrew Morton wrote:
> 
> > * something is wrong in the vortex initialization: I don't have such a
> > card, but the driver didn't return an error message on insmod. I'm not
> > sure if my fix is correct.
> 
> That was intentional - dhinds suggested that if the hardware
> isn't present the driver should float about in memory anyway.

Say the driver is linked into the kernel.  Hot plug drivers should not
all complain about not finding their hardware.

-- Dave

Re: [PATCH] network driver updates

[Jeff Garzik]

On Wed, 14 Feb 2001, David Hinds wrote:
> On Thu, Feb 15, 2001 at 12:33:43AM +1100, Andrew Morton wrote:
> > 
> > > * something is wrong in the vortex initialization: I don't have such a
> > > card, but the driver didn't return an error message on insmod. I'm not
> > > sure if my fix is correct.
> > 
> > That was intentional - dhinds suggested that if the hardware
> > isn't present the driver should float about in memory anyway.
> 
> Say the driver is linked into the kernel.  Hot plug drivers should not
> all complain about not finding their hardware.

Yes; that is the whole reason why pci_register_driver does not error out
when it finds zero matching devices.

	Jeff

Re: [PATCH] network driver updates

[Manfred Spraul]

[-- Attachment #1: Type: text/plain, Size: 593 bytes --]

David Hinds wrote:
> 
> Say the driver is linked into the kernel.  Hot plug drivers should not
> all complain about not finding their hardware.
>

That's handled by pci_module_init(), check <linux/pci.h>:
if CONFIG_HOTPLUG is enabled, then pci_module_init() never returns with
-ENODEV.

Which means that eisa cards will never be probed in a hotplug enabled
kernel.

And loading the current 3c59x.c into a non CONFIG_HOTPLUG non EISA
kernel results in a disconnected driver:
it's _not_ registered as a pci driver, pci_module_init() calls
pci_unregister_driver().

What about the attached patch?

[-- Attachment #2: patch-hinds --]
[-- Type: text/plain, Size: 432 bytes --]

--- 2.4/drivers/net/3c59x.c	Wed Feb 14 10:50:50 2001
+++ build-2.4/drivers/net/3c59x.c	Wed Feb 14 18:51:55 2001
@@ -2661,13 +2661,16 @@
 	
 	rc = pci_module_init(&vortex_driver);
 	if (rc < 0) {
-		rc = vortex_eisa_init();
-		if (rc > 0)
-			vortex_have_eisa = 1;
+		if (rc != -ENODEV)
+			return rc;
 	} else {
 		vortex_have_pci = 1;
 	}
 
+	if (vortex_eisa_init() > 0) {
+		vortex_have_eisa = 1;
+		rc = 0;
+	}
 	return rc;
 }
 

Re: [PATCH] network driver updates

[Andrew Morton]

Manfred Spraul wrote:
> 
> David Hinds wrote:
> >
> > Say the driver is linked into the kernel.  Hot plug drivers should not
> > all complain about not finding their hardware.
> >
> 
> That's handled by pci_module_init(), check <linux/pci.h>:
> if CONFIG_HOTPLUG is enabled, then pci_module_init() never returns with
> -ENODEV.
> 
> Which means that eisa cards will never be probed in a hotplug enabled
> kernel.
> 
> And loading the current 3c59x.c into a non CONFIG_HOTPLUG non EISA
> kernel results in a disconnected driver:
> it's _not_ registered as a pci driver, pci_module_init() calls
> pci_unregister_driver().

That's what we want to happen, isn't it?  If it's not a hotplug
kernel and the hardware isn't there at boot time, don't register
the PCI driver.  But still scan for EISA devices.  That's what
the patch I sent yesterday does.  Here it is:

static int __init vortex_init (void)
{
    int pci_rc, eisa_rc;

    pci_rc = pci_module_init(&vortex_driver);
    eisa_rc = vortex_eisa_init();

    if (pci_rc == 0)
        vortex_have_pci = 1;
    if (eisa_rc > 0)
        vortex_have_eisa = 1;

    return (vortex_have_pci + vortex_have_eisa) ? 0 : -ENODEV;
}

Really, vortex_have_pci should be called
vortex_have_pci_or_hotplug_and_dont_have_pci.

Look.  When the driver's init_module() method is called
there are four combinations which must be catered for
(ignoring EISA):

CONFIG_HOTPLUG=n, MODULE=false
	If the hardware isn't there, don't register
        the pci_driver.  It can't _do_ anything.

CONFIG_HOTPLUG=n, MODULE=true
	If the hardware isn't there, barf.  modprobe will
        remove the driver again.

CONFIG_HOTPLUG=y, MODULE=false
        If the hardware isn't there, register the pci
        driver, because the hardware may appear later

CONFIG_HOTPLUG=y, MODULE=true
        If the hardware isn't there, barf. modprobe will remove
        the driver.  Later, when the hardware is inserted, another
        modprobe will succeed.

This is what yesterday's patch implements.

Now, the thing I don't understand about David's design is the
final one.  What 3c575_cb does is:

CONFIG_HOTPLUG=y, MODULE=true
         If the hardware isn't there, register the driver and
         hang around.

Why?


BTW: How come CONFIG_PCMCIA requires CONFIG_HOTPLUG?  Doesn't
it make sense to be able to have glued-in Cardbus devices?


-

Re: [PATCH] network driver updates

[David Hinds]

On Thu, Feb 15, 2001 at 10:49:22PM +1100, Andrew Morton wrote:
> 
> Now, the thing I don't understand about David's design is the
> final one.  What 3c575_cb does is:
> 
> CONFIG_HOTPLUG=y, MODULE=true
>          If the hardware isn't there, register the driver and
>          hang around.
> 
> Why?

Merely that I was trying to disassociate the concepts of module
loading and device probing, and I thought it was most consistent to
then allow people to load modules whenever they want, whether or not a
device was present.

> BTW: How come CONFIG_PCMCIA requires CONFIG_HOTPLUG?  Doesn't
> it make sense to be able to have glued-in Cardbus devices?

I suppose it makes sense but I don't know if it is something worth the
trouble of supporting.

-- Dave

Re: [PATCH] network driver updates

[Andrew Morton]

David Hinds wrote:
> 
> On Thu, Feb 15, 2001 at 10:49:22PM +1100, Andrew Morton wrote:
> >
> > Now, the thing I don't understand about David's design is the
> > final one.  What 3c575_cb does is:
> >
> > CONFIG_HOTPLUG=y, MODULE=true
> >          If the hardware isn't there, register the driver and
> >          hang around.
> >
> > Why?
> 
> Merely that I was trying to disassociate the concepts of module
> loading and device probing, and I thought it was most consistent to
> then allow people to load modules whenever they want, whether or not a
> device was present.

Fair enough.  Thanks.

Another scenario may be where (say) a network driver is modprobed
from a hotpluggable disk controller.  You want to be able to load
the netdriver, pop out the disk controller and then insert the network
card.  Or vice-versa - load a parallel port driver across NFS then
pull the network card and push the parallel port card.  Could use
local disks for this, of course.

hmm..