Tim Waugh (tim@cyberelk.demon.co.uk)
Mon, 26 Jul 1999 20:52:43 +0100 (GMT)
On Mon, 26 Jul 1999, Thomas Sailer wrote:
> Another issue: the parport probing routines play games with
> parport_pc_ops, replacing method pointers there, and then a reference
> to parport_pc_ops is stored in parport->ops. Doesn't that mean that
> all PC parports share the same method table? That does only work if
> all ports have the same hw capabilities...
I've fixed that now, and while I was about it I've made unregistered ports
that still have registered device drivers persist until the device drivers
take notice of the detach() call on them.
Tim.
*/
diff -durN linux-current/drivers/parport/parport_pc.c linux/drivers/parport/parport_pc.c
--- linux-current/drivers/parport/parport_pc.c Mon Jul 26 16:55:03 1999
+++ linux/drivers/parport/parport_pc.c Mon Jul 26 20:42:58 1999
@@ -1521,6 +1521,7 @@
int irq, int dma)
{
struct parport_pc_private *priv;
+ struct parport_operations *ops;
struct parport tmp;
struct parport *p = &tmp;
int probedirq = PARPORT_IRQ_NONE;
@@ -1530,6 +1531,14 @@
printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base);
return 0;
}
+ ops = kmalloc (sizeof (struct parport_operations), GFP_KERNEL);
+ if (!ops) {
+ printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
+ base);
+ kfree (priv);
+ return 0;
+ }
+ memcpy (ops, &parport_pc_ops, sizeof (struct parport_operations));
priv->ctr = 0xc;
priv->ctr_writable = 0xff;
priv->ecr = 0;
@@ -1540,7 +1549,7 @@
p->irq = irq;
p->dma = dma;
p->modes = PARPORT_MODE_PCSPP;
- p->ops = &parport_pc_ops;
+ p->ops = ops;
p->private_data = priv;
p->physport = p;
if (base_hi && !check_region(base_hi,3)) {
@@ -1564,8 +1573,9 @@
parport_PS2_supported (p);
if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
- PARPORT_DMA_NONE, &parport_pc_ops))) {
+ PARPORT_DMA_NONE, ops))) {
kfree (priv);
+ kfree (ops);
return 0;
}
@@ -1896,6 +1906,7 @@
if (priv->dma_buf)
free_page((unsigned long) priv->dma_buf);
kfree (p->private_data);
+ kfree (p->ops); /* hope no-one cached it */
parport_unregister_port(p);
}
p = tmp;
diff -durN linux-current/drivers/parport/share.c linux/drivers/parport/share.c
--- linux-current/drivers/parport/share.c Mon Jul 26 16:55:03 1999
+++ linux/drivers/parport/share.c Mon Jul 26 20:27:30 1999
@@ -41,6 +41,51 @@
static struct parport_driver *driver_chain = NULL;
spinlock_t driverlist_lock = SPIN_LOCK_UNLOCKED;
+/* What you can do to a port that's gone away.. */
+static void dead_write_lines (struct parport *p, unsigned char b){}
+static unsigned char dead_read_lines (struct parport *p) { return 0; }
+static unsigned char dead_frob_lines (struct parport *p, unsigned char b,
+ unsigned char c) { return 0; }
+static void dead_onearg (struct parport *p){}
+static void dead_irq (int i, void *p, struct pt_regs *r) { }
+static void dead_initstate (struct pardevice *d, struct parport_state *s) { }
+static void dead_state (struct parport *p, struct parport_state *s) { }
+static void dead_noargs (void) { }
+static void dead_fill (struct inode *i, int f) { }
+static size_t dead_write (struct parport *p, const void *b, size_t l, int f)
+{ return 0; }
+static size_t dead_read (struct parport *p, void *b, size_t l, int f)
+{ return 0; }
+static struct parport_operations dead_ops = {
+ dead_write_lines, /* data */
+ dead_read_lines,
+ dead_write_lines, /* control */
+ dead_read_lines,
+ dead_frob_lines,
+ dead_read_lines, /* status */
+ dead_onearg, /* enable_irq */
+ dead_onearg, /* disable_irq */
+ dead_onearg, /* data_forward */
+ dead_onearg, /* data_reverse */
+ dead_irq,
+ dead_initstate, /* init_state */
+ dead_state,
+ dead_state,
+ dead_noargs, /* xxx_use_count */
+ dead_noargs,
+ dead_fill, /* fill_inode */
+ dead_write, /* epp */
+ dead_read,
+ dead_write,
+ dead_read,
+ dead_write, /* ecp */
+ dead_read,
+ dead_write,
+ dead_write, /* compat */
+ dead_read, /* nibble */
+ dead_read /* byte */
+};
+
static void call_driver_chain(int attach, struct parport *port)
{
struct parport_driver *drv;
@@ -188,10 +233,31 @@
call_driver_chain (1, port);
}
+static void free_port (struct parport *port)
+{
+ int d;
+ for (d = 0; d < 5; d++) {
+ if (port->probe_info[d].class_name)
+ kfree (port->probe_info[d].class_name);
+ if (port->probe_info[d].mfr)
+ kfree (port->probe_info[d].mfr);
+ if (port->probe_info[d].model)
+ kfree (port->probe_info[d].model);
+ if (port->probe_info[d].cmdset)
+ kfree (port->probe_info[d].cmdset);
+ if (port->probe_info[d].description)
+ kfree (port->probe_info[d].description);
+ }
+
+ kfree(port->name);
+ kfree(port);
+}
+
void parport_unregister_port(struct parport *port)
{
struct parport *p;
- int d;
+
+ port->ops = &dead_ops;
/* Spread the word. */
call_driver_chain (0, port);
@@ -217,21 +283,8 @@
}
spin_unlock(&parportlist_lock);
- for (d = 0; d < 5; d++) {
- if (port->probe_info[d].class_name)
- kfree (port->probe_info[d].class_name);
- if (port->probe_info[d].mfr)
- kfree (port->probe_info[d].mfr);
- if (port->probe_info[d].model)
- kfree (port->probe_info[d].model);
- if (port->probe_info[d].cmdset)
- kfree (port->probe_info[d].cmdset);
- if (port->probe_info[d].description)
- kfree (port->probe_info[d].description);
- }
-
- kfree(port->name);
- kfree(port);
+ if (!port->devices)
+ free_port (port);
}
struct pardevice *parport_register_device(struct parport *port, const char *name,
@@ -361,6 +414,11 @@
dec_parport_count();
port->ops->dec_use_count();
+
+ /* If this was the last device on a port that's already gone away,
+ * free up the resources. */
+ if (port->ops == &dead_ops && !port->devices)
+ free_port (port);
}
int parport_claim(struct pardevice *dev)
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This archive was generated by hypermail 2.0b3 on Mon 26 Jul 1999 - 15:56:35 EDT