Attachment 78105 Details for Bug 146438

[patch] fix the subordinate number of the parent bridge in yenta_socket_probe within limits

yenta-fixup-parent-bridge.patch (text/plain), 4.23 KB, created by Bernhard Kaindl on 2006-04-12 19:07:07 UTC

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Creator: Bernhard Kaindl

Created: 2006-04-12 19:07:07 UTC

Size: 4.23 KB

patch

obsolete

>Fixup the subordinate number parent bridge of yenta Cardbus Bridges
>before the PCI bus scan starts to make the cardbus cards which are
>otherwise hidden for PCI scans work.
>
>Affected systems (from an internet search):
>* ASUS Z71V and L3s
>* Samsung X20 (fixed in latest BIOS, but older BIOSes are affected)
>* Compaq R3140us and all Compaq R3000 series laptops with TI1620 Controller
>  (AMD64-based Laptops), also Compaq R4000 series
>* HP zv5000z (AMD64 3700+, known that fixup_parent_subordinate_busnr fixes it)
>* HP zv5200z
>* IBM ThinkPad 240
>* An IBM ThinkPad (1.8 GHz Pentium M) debugged by Pavel Machek
>  gives the correspondig message which detects the problem.
>* MSI S260 / Medion SIM 2100 MD 95600
>
>Signed-off-by: Bernhard Kaindl <bk@suse.de>
>
>--- linux-2.6.16/drivers/pcmcia/yenta_socket.c
>+++ linux-2.6.16/drivers/pcmcia/yenta_socket.c	2006/04/08 11:51:20
>@@ -998,6 +998,78 @@
> 	config_writew(socket, CB_BRIDGE_CONTROL, bridge);
> }
>
>+/**
>+ * yenta_fixup_parent_subordinate - Fix subordinate bus# of the parent bridge
>+ * @cardbus_bridge: The PCI bus which the CardBus bridge bridges to
>+ *
>+ * Checks if devices on the bus which the CardBus bridge bridges to would be
>+ * invisible during PCI scans because of a misconfigured subordinate number
>+ * of the parent brige - some BIOSes seem to be too lazy to set it right.
>+ * Does the fixup carefully by checking how far it can go without conflicts.
>+ * See http://bugzilla.kernel.org/show_bug.cgi?id=2944 for more information.
>+ */
>+static void yenta_fixup_parent_bridge(struct pci_bus *cardbus_bridge)
>+{
>+	struct list_head *tmp;
>+	/* Our starting point is the max PCI bus number */
>+	unsigned char upper_limit = 0xff;
>+ 	/*
>+	 * We only check and fix the parent bridge: All systems which need
>+	 * this fixup that have been reviewed are laptops and the only bridge
>+	 * which needed fixing was the parent bridge of the CardBus bridge:
>+	 */
>+	struct pci_bus *bridge_to_fix = cardbus_bridge->parent;
>+
>+	/* Check bus numbers are already set up correctly: */
>+	if (bridge_to_fix->subordinate >= cardbus_bridge->subordinate)
>+		return; /* The subordinate number is ok, nothing to do */
>+
>+	if (!bridge_to_fix->parent)
>+		return; /* Root bridges are ok */
>+
>+	/* stay within the limits of the bus range of the parent: */
>+	upper_limit = bridge_to_fix->parent->subordinate;
>+
>+	/* check the bus ranges of all silbling bridges to prevent overlap */
>+	list_for_each(tmp, &bridge_to_fix->parent->children) {
>+		struct pci_bus * silbling = pci_bus_b(tmp);
>+		/*
>+		 * If the silbling has a higher secondary bus number
>+		 * and it's secondary is equal or smaller than our
>+		 * current upper limit, set the new upper limit to
>+		 * the bus number below the silbling's range:
>+		 */
>+		if (silbling->secondary > bridge_to_fix->subordinate
>+		    && silbling->secondary <= upper_limit)
>+			upper_limit = silbling->secondary - 1;
>+	}
>+
>+	/* Show that the wanted subordinate number is not possible: */
>+	if (cardbus_bridge->subordinate > upper_limit)
>+		printk(KERN_WARNING "Yenta: Upper limit for fixing this "
>+			"bridge's parent bridge: #%02x\n", upper_limit);
>+
>+	/* If we have room to increase the bridge's subordinate number, */
>+	if (bridge_to_fix->subordinate < upper_limit) {
>+
>+		/* use the highest number of the hidden bus, within limits */
>+		unsigned char subordinate_to_assign =
>+			min(cardbus_bridge->subordinate, upper_limit);
>+
>+		printk(KERN_INFO "Yenta: Raising subordinate bus# of parent "
>+			"bus (#%02x) from #%02x to #%02x\n",
>+			bridge_to_fix->number,
>+			bridge_to_fix->subordinate, subordinate_to_assign);
>+
>+		/* Save the new subordinate in the bus struct of the bridge */
>+		bridge_to_fix->subordinate = subordinate_to_assign;
>+
>+		/* and update the PCI config space with the new subordinate */
>+		pci_write_config_byte(bridge_to_fix->self,
>+			PCI_SUBORDINATE_BUS, bridge_to_fix->subordinate);
>+	}
>+}
>+
> /*
>  * Initialize a cardbus controller. Make sure we have a usable
>  * interrupt, and that we can map the cardbus area. Fill in the
>@@ -1113,6 +1184,8 @@
> 	yenta_get_socket_capabilities(socket, isa_interrupts);
> 	printk(KERN_INFO "Socket status: %08x\n", cb_readl(socket, CB_SOCKET_STATE));
>
>+	yenta_fixup_parent_bridge(dev->subordinate);
>+
> 	/* Register it with the pcmcia layer.. */
> 	ret = pcmcia_register_socket(&socket->socket);
> 	if (ret == 0) {

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