olpc: sdhci: add quirk for the Marvell CaFe's interrupt timeout

The CaFe chip has a hardware bug that ends up with us getting a timeout
value that's too small, causing the following sorts of problems:

[ 60.525138] mmcblk0: error -110 transferring data
[ 60.531477] end_request: I/O error, dev mmcblk0, sector 1484353
[ 60.533371] Buffer I/O error on device mmcblk0p2, logical block 181632
[ 60.533371] lost page write due to I/O error on mmcblk0p2

Presumably this is an off-by-one error in the hardware. Incrementing
the timeout count value that we stuff into the TIMEOUT_CONTROL register
gets us a value that works. This bug was originally discovered by
Pierre Ossman, I believe.

[thanks to Robert Millan for proving that this was still a problem]

Signed-off-by: Andres Salomon <[e-mail]>
Cc: Pierre Ossman <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/mmc/host/sdhci.c

···
 #define SDHCI_QUIRK_RESET_AFTER_REQUEST			(1<<8)
 /* Controller needs voltage and power writes to happen separately */
 #define SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER		(1<<9)
+/* Controller has an off-by-one issue with timeout value */
+#define SDHCI_QUIRK_INCR_TIMEOUT_CONTROL		(1<<10)
 
 static const struct pci_device_id pci_ids[] __devinitdata = {
 	{
···
 		.device         = PCI_DEVICE_ID_MARVELL_CAFE_SD,
 		.subvendor      = PCI_ANY_ID,
 		.subdevice      = PCI_ANY_ID,
-		.driver_data    = SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER,
+		.driver_data    = SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER |
+				  SDHCI_QUIRK_INCR_TIMEOUT_CONTROL,
 	},
 
 	{
···
 		if (count >= 0xF)
 			break;
 	}
+
+	/*
+	 * Compensate for an off-by-one error in the CaFe hardware; otherwise,
+	 * a too-small count gives us interrupt timeouts.
+	 */
+	if ((host->chip->quirks & SDHCI_QUIRK_INCR_TIMEOUT_CONTROL))
+		count++;
 
 	if (count >= 0xF) {
 		printk(KERN_WARNING "%s: Too large timeout requested!\n",