CardBus card not recognized

[Martin Mares]

Hello, world!\n

I've just tried Linux 2.6.11.11 on my ancient Thinkpad 560X (TI 1250 CardBus
bridge) and it doesn't recognize any CardBus card. After some experimenting
(well, about one afternoon :) ), it turned out that the first access to the
configuration space of the card after configuring the slot returns 0xffffffff.

Waiting for a while doesn't help, but reading the vendor and device ID before
probing the PCI slot, as done by the attached patch, makes the devices
detected correctly.

To be honest, I don't understand why does this happen, so maybe I'm overlooking
a deeper problem.
 
				Have a nice fortnight
-- 
Martin `MJ' Mares   <mj at ucw.cz>   http://atrey.karlin.mff.cuni.cz/~mj/
Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth
"In accord to UNIX philosophy, PERL gives you enough rope to hang yourself." -- Larry Wall


diff -ru linux-2.6.11/drivers/pcmcia/cardbus.c linux-2.6.11.11-abacus/drivers/pcmcia/cardbus.c
--- linux-2.6.11.11/drivers/pcmcia/cardbus.c	2005-04-22 13:04:52 +0200
+++ linux-2.6.11.11-abacus/drivers/pcmcia/cardbus.c	2005-06-02 19:48:18 +0200
@@ -213,6 +213,10 @@
 	struct pci_dev *dev;
 	unsigned int max, pass;
 
+	/* The first access tends to fail on some bridges, so do something harmless. --MJ */
+	u32 l;
+	pci_bus_read_config_dword(bus, PCI_DEVFN(0, 0), PCI_VENDOR_ID, &l);
+
 	s->functions = pci_scan_slot(bus, PCI_DEVFN(0, 0));
 //	pcibios_fixup_bus(bus);