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| author | Clemens Ladisch <clemens@ladisch.de> | 2010-06-10 08:40:49 +0200 |
|---|---|---|
| committer | Clemens Ladisch <clemens@ladisch.de> | 2010-06-10 08:40:49 +0200 |
| commit | e91b2787d0a2e4719b016e8dec0afd2d5ab6c30f (patch) | |
| tree | e76a3665243ed9fb7275228d9a14dcb0eb5b567a /drivers/firewire/ohci.c | |
| parent | 7e0e314f198d5048b74c8f0ef9f4c1c02e5ecfc9 (diff) | |
| download | kernel_samsung_tuna-e91b2787d0a2e4719b016e8dec0afd2d5ab6c30f.zip kernel_samsung_tuna-e91b2787d0a2e4719b016e8dec0afd2d5ab6c30f.tar.gz kernel_samsung_tuna-e91b2787d0a2e4719b016e8dec0afd2d5ab6c30f.tar.bz2 | |
firewire: allocate broadcast channel in hardware
On OHCI 1.1 controllers, let the hardware allocate the broadcast channel
automatically. This removes a theoretical race condition directly after
a bus reset where it could be possible to read the channel allocation
register with channel 31 still being unallocated.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'drivers/firewire/ohci.c')
| -rw-r--r-- | drivers/firewire/ohci.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 1dcc2e4..51a5580 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -171,6 +171,7 @@ struct fw_ohci { int request_generation; /* for timestamping incoming requests */ unsigned quirks; unsigned int pri_req_max; + unsigned int features; u32 bus_time; bool is_root; @@ -1694,7 +1695,7 @@ static int ohci_enable(struct fw_card *card, { struct fw_ohci *ohci = fw_ohci(card); struct pci_dev *dev = to_pci_dev(card->device); - u32 lps, seconds, irqs; + u32 lps, seconds, version, irqs; int i, ret; if (software_reset(ohci)) { @@ -1747,10 +1748,19 @@ static int ohci_enable(struct fw_card *card, reg_write(ohci, OHCI1394_IsochronousCycleTimer, seconds << 25); ohci->bus_time = seconds & ~0x3f; + version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff; + if (version >= OHCI_VERSION_1_1) { + reg_write(ohci, OHCI1394_InitialChannelsAvailableHi, + 0xfffffffe); + ohci->features |= FEATURE_CHANNEL_31_ALLOCATED; + } + /* Get implemented bits of the priority arbitration request counter. */ reg_write(ohci, OHCI1394_FairnessControl, 0x3f); ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f; reg_write(ohci, OHCI1394_FairnessControl, 0); + if (ohci->pri_req_max != 0) + ohci->features |= FEATURE_PRIORITY_BUDGET; ar_context_run(&ohci->ar_request_ctx); ar_context_run(&ohci->ar_response_ctx); @@ -2124,12 +2134,8 @@ static void ohci_write_csr_reg(struct fw_card *card, int csr_offset, u32 value) static unsigned int ohci_get_features(struct fw_card *card) { struct fw_ohci *ohci = fw_ohci(card); - unsigned int features = 0; - - if (ohci->pri_req_max != 0) - features |= FEATURE_PRIORITY_BUDGET; - return features; + return ohci->features; } static void copy_iso_headers(struct iso_context *ctx, void *p) |