Re: Firewire Disk Broken in 2.4.19-pre8-ben0 kernel (was working fine with 2.4.18-ben0)

Hi Michel,

Nice shot!  It works again with the ieee1394-473 tarball (or the distributed
2.4.19-pre8 ieee1394 code) and the change you suggested.  Thanks a ton!!!

						-Bill



On Tue, 14 May 2002, Michel Lanners wrote:

Shot in the dark....

On  14 May, this message from Bill Fink echoed through cyberspace:

quoted

diff -u ieee1394-022602/hosts.c ieee1394-022702/hosts.c

--- ieee1394-022602/hosts.c	Sat Feb  9 00:41:40 2002
+++ ieee1394-022702/hosts.c	Tue Feb 26 15:06:39 2002

@@ -78,26 +97,39 @@
         spin_unlock_irqrestore(&hosts_lock, flags);
 }

+/**
+ * hpsb_alloc_host - allocate a new host controller.
+ * @drv: the driver that will manage the host controller
+ * @extra: number of extra bytes to allocate for the driver
+ *
+ * Allocate a &hpsb_host and initialize the general subsystem specific
+ * fields.  If the driver needs to store per host data, as drivers
+ * usually do, the amount of memory required can be specified by the
+ * @extra parameter.  Once allocated, the driver should initialize the
+ * driver specific parts, enable the controller and make it available
+ * to the general subsystem using hpsb_add_host().
+ *
+ * The &hpsb_host is allocated with an single initial reference
+ * belonging to the driver.  Once the driver is done with the struct,
+ * for example, when the driver is unloaded, it should release this
+ * reference using hpsb_unref_host().
+ *
+ * Return Value: a pointer to the &hpsb_host if succesful, %NULL if
+ * no memory was available.
+ */
+
 struct hpsb_host *hpsb_alloc_host(struct hpsb_host_driver *drv, size_t extra)
 {
         struct hpsb_host *h;

-        h = kmalloc(sizeof(struct hpsb_host), SLAB_KERNEL);
+        h = kmalloc(sizeof(struct hpsb_host) + extra, SLAB_KERNEL);
         if (!h) return NULL;
         memset(h, 0, sizeof(struct hpsb_host));

                        ^^^^^^^^^^^^^^^^^^^^^^^^
This should probably be sizeof(struct hpsb_host) + extra.

quoted

-	/* Drivers usually use this to allocate their private data */
-	if (extra) {
-		h->hostdata = kmalloc(extra, SLAB_KERNEL);
-		if (!h->hostdata) {
-			kfree(h);
-			return NULL;
-		}
-		memset(h->hostdata, 0, extra);
-	}
-
+	h->hostdata = h + 1;
         h->driver = drv;
         h->ops = drv->ops;
+	h->refcount = 1;

         INIT_LIST_HEAD(&h->pending_packets);
         spin_lock_init(&h->pending_pkt_lock);

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