Date: Sun, 14 Feb 2010 18:47:07 +0100 (CET) From: Stefan Richter Subject: firewire: ohci: enable cycle timer fix on ALi and NEC controllers Discussed in "read_cycle_timer backwards for sub-cycle 0000, 0001", http://thread.gmane.org/gmane.linux.kernel.firewire.devel/13704 Known bad controllers: ALi M5271, listed by lspci as M5253 [10b9:5253] NEC OrangeLink [1033:00cd] (rev 03) NEC uPD72874 [1033:00f2] (rev 01) VIA VT6306 [1106:3044] (rev 46) VIA VT6308P, listed by lspci as rev c0 Reported-by: Pieter Palmers Reported-by: Håkan Johansson Reported-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) Index: linux-2.6.33-rc8/drivers/firewire/ohci.c =================================================================== --- linux-2.6.33-rc8.orig/drivers/firewire/ohci.c +++ linux-2.6.33-rc8/drivers/firewire/ohci.c @@ -1817,13 +1817,14 @@ static u64 ohci_get_bus_time(struct fw_c c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer); } else { /* - * VIA controllers have two bugs when updating the iso cycle - * timer register: - * 1) When the lowest six bits are wrapping around to zero, + * Some controllers exhibit one or more of the following bugs + * when updating the iso cycle timer register: + * - When the lowest six bits are wrapping around to zero, * a read that happens at the same time will return garbage * in the lowest ten bits. - * 2) When the cycleOffset field wraps around to zero, the + * - When the cycleOffset field wraps around to zero, the * cycleCount field is not incremented for about 60 ns. + * - Occasionally, the entire register reads zero. * * To catch these, we read the register three times and ensure * that the difference between each two consecutive reads is @@ -2547,7 +2548,9 @@ static int __devinit pci_probe(struct pc #endif ohci->bus_reset_packet_quirk = dev->vendor == PCI_VENDOR_ID_TI; - ohci->iso_cycle_timer_quirk = dev->vendor == PCI_VENDOR_ID_VIA; + ohci->iso_cycle_timer_quirk = dev->vendor == PCI_VENDOR_ID_AL || + dev->vendor == PCI_VENDOR_ID_NEC || + dev->vendor == PCI_VENDOR_ID_VIA; ar_context_init(&ohci->ar_request_ctx, ohci, OHCI1394_AsReqRcvContextControlSet);