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>

3 files changed, 9 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 5cb775b1802d..f644ba9529ed 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/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;
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index bc94d7bf072d..4baafa3e80b2 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/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 */
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 2694ed6558d2..2a6652fd5400 100644
--- a/drivers/usb/host/ehci.h
+++ b/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)