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authorStefan Richter <stefanr@s5r6.in-berlin.de>2009-08-28 13:25:15 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-09-05 15:59:34 +0200
commitfc383796a8cc5df0a0c8633a16dd2e9528a16a63 (patch)
tree92a231d28de6d396246a1136099d896a37be2332
parent1821bc19d54009b6f5e6462dd79074d728080839 (diff)
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firewire: ohci: fix Agere FW643 and multiple cameras
An Agere FW643 OHCI 1.1 card works fine for video reception from one camera but fails early if receiving from two cameras. After a short while, no IR IRQ events occur and the context control register does not react anymore. This happens regardless whether both IR DMA contexts are dual-buffer or one is dual-buffer and the other packet-per-buffer. This can be worked around by disabling dual buffer DMA mode entirely. http://sourceforge.net/mailarchive/message.php?msg_name=4A7C0594.2020208%40gmail.com (Reported by Samuel Audet.) In another report (by Jonathan Cameron), an FW643 works OK with two cameras in dual buffer mode. Whether this is due to different chip revisions or different usage patterns (different video formats) is not yet clear. However, as far as the current capabilities of firewire-core's isochronous I/O interface are concerned, simply switching off dual-buffer on non-working and working FW643s alike is not a problem in practice. We only need to revisit this issue if we are going to enhance the interface, e.g. so that applications can explicitly choose modes. Reported-by: Samuel Audet <samuel.audet@gmail.com> Reported-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
-rw-r--r--drivers/firewire/ohci.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index ecddd11b797..3486bc49c17 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -34,6 +34,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
+#include <linux/pci_ids.h>
#include <linux/spinlock.h>
#include <linux/string.h>
@@ -2372,6 +2373,9 @@ static void ohci_pmac_off(struct pci_dev *dev)
#define ohci_pmac_off(dev)
#endif /* CONFIG_PPC_PMAC */
+#define PCI_VENDOR_ID_AGERE PCI_VENDOR_ID_ATT
+#define PCI_DEVICE_ID_AGERE_FW643 0x5901
+
static int __devinit pci_probe(struct pci_dev *dev,
const struct pci_device_id *ent)
{
@@ -2422,6 +2426,11 @@ static int __devinit pci_probe(struct pci_dev *dev,
version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
ohci->use_dualbuffer = version >= OHCI_VERSION_1_1;
+ /* dual-buffer mode is broken if more than one IR context is active */
+ if (dev->vendor == PCI_VENDOR_ID_AGERE &&
+ dev->device == PCI_DEVICE_ID_AGERE_FW643)
+ ohci->use_dualbuffer = false;
+
/* x86-32 currently doesn't use highmem for dma_alloc_coherent */
#if !defined(CONFIG_X86_32)
/* dual-buffer mode is broken with descriptor addresses above 2G */