diff options
| -rw-r--r-- | Documentation/debugging-via-ohci1394.txt | 13 | ||||
| -rw-r--r-- | drivers/firewire/core.h | 4 | ||||
| -rw-r--r-- | drivers/firewire/ohci.c | 2 |
3 files changed, 11 insertions, 8 deletions
diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt index fa0151a712f..5c9a567b3fa 100644 --- a/Documentation/debugging-via-ohci1394.txt +++ b/Documentation/debugging-via-ohci1394.txt @@ -25,9 +25,11 @@ using data transfer rates in the order of 10MB/s or more. With most FireWire controllers, memory access is limited to the low 4 GB of physical address space. This can be a problem on IA64 machines where memory is located mostly above that limit, but it is rarely a problem on -more common hardware such as x86, x86-64 and PowerPC. However, at least -Agere/LSI FW643e and FW643e2 controllers are known to support access to -physical addresses above 4 GB. +more common hardware such as x86, x86-64 and PowerPC. + +At least LSI FW643e and FW643e2 controllers are known to support access to +physical addresses above 4 GB, but this feature is currently not enabled by +Linux. Together with a early initialization of the OHCI-1394 controller for debugging, this facility proved most useful for examining long debugs logs in the printk @@ -101,8 +103,9 @@ Step-by-step instructions for using firescope with early OHCI initialization: compliant, they are based on TI PCILynx chips and require drivers for Win- dows operating systems. - The mentioned kernel log message contains ">4 GB phys DMA" in case of - OHCI-1394 controllers which support accesses above this limit. + The mentioned kernel log message contains the string "physUB" if the + controller implements a writable Physical Upper Bound register. This is + required for physical DMA above 4 GB (but not utilized by Linux yet). 2) Establish a working FireWire cable connection: diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h index c98764aeeec..f477308b6e9 100644 --- a/drivers/firewire/core.h +++ b/drivers/firewire/core.h @@ -237,8 +237,8 @@ static inline bool is_next_generation(int new_generation, int old_generation) #define LOCAL_BUS 0xffc0 -/* arbitrarily chosen maximum range for physical DMA: 128 TB */ -#define FW_MAX_PHYSICAL_RANGE (128ULL << 40) +/* OHCI-1394's default upper bound for physical DMA: 4 GB */ +#define FW_MAX_PHYSICAL_RANGE (1ULL << 32) void fw_core_handle_request(struct fw_card *card, struct fw_packet *request); void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet); diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 8db66321956..586f2f7f699 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -3716,7 +3716,7 @@ static int pci_probe(struct pci_dev *dev, version >> 16, version & 0xff, ohci->card.index, ohci->n_ir, ohci->n_it, ohci->quirks, reg_read(ohci, OHCI1394_PhyUpperBound) ? - ", >4 GB phys DMA" : ""); + ", physUB" : ""); return 0; |