USB: EHCI: work around bug in the Philips ISP1562 controller

This patch (as1556) works around a bug in the Philips ISP1562 EHCI
controller.  Although the controller claims to support frame-list
lengths smaller than the default of 1024 for its periodic schedule, in
fact smaller values don't work.  A new quirk flag is added to indicate
when the bug is present, and if it is then the schedule size is left
at the default value.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-hcd.c

@@ -639,7 +639,7 @@ static int ehci_init(struct usb_hcd *hcd)
 	INIT_LIST_HEAD(&ehci->cached_itd_list);
 	INIT_LIST_HEAD(&ehci->cached_sitd_list);
 
-	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+	if (HCC_PGM_FRAMELISTLEN(hcc_params) && !ehci->sched_size_bug) {
 		/* periodic schedule size can be smaller than default */
 		switch (EHCI_TUNE_FLS) {
 		case 0: ehci->periodic_size = 1024; break;

drivers/usb/host/ehci-pci.c

@@ -97,6 +97,13 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
 			break;
 		}
 		break;
+
+	case PCI_VENDOR_ID_PHILIPS:
+		/*
+		 * Philips controllers set HCC_PGM_FRAMELISTLEN, but
+		 * they don't implement schedule sizes shorter than 1024.
+		 */
+		ehci->sched_size_bug = 1;
 	}
 
 	/* cache this readonly data; minimize chip reads */

drivers/usb/host/ehci.h

@@ -149,6 +149,7 @@ struct ehci_hcd {			/* one per controller */
 	unsigned		use_dummy_qh:1;	/* AMD Frame List table quirk*/
 	unsigned		has_synopsys_hc_bug:1; /* Synopsys HC */
 	unsigned		frame_index_bug:1; /* MosChip (AKA NetMos) */
+	unsigned		sched_size_bug:1; /* Philips */
 
 	/* required for usb32 quirk */
 	#define OHCI_CTRL_HCFS          (3 << 6)