Date: Thu, 01 Apr 2010 16:43:59 +0200 From: Clemens Ladisch Subject: firewire: ohci: fix up configuration of TI chips On TI chips (OHCI-Lynx and later), enable link enhancements features that TI recommends to be used. None of these are required for proper operation, but they are safe and nice to have. In theory, these bits should have been set by default, but in practice, some BIOS/EEPROM writers apparently do not read the datasheet, or get spooked by names like "unfair". Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 19 ++++++++++++++++++- drivers/firewire/ohci.h | 8 ++++++++ 2 files changed, 26 insertions(+), 1 deletion(-) Index: b/drivers/firewire/ohci.c =================================================================== --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2431,7 +2431,7 @@ static int __devinit pci_probe(struct pc const struct pci_device_id *ent) { struct fw_ohci *ohci; - u32 bus_options, max_receive, link_speed, version; + u32 bus_options, max_receive, link_speed, version, link_enh; u64 guid; int i, err, n_ir, n_it; size_t size; @@ -2484,6 +2484,23 @@ static int __devinit pci_probe(struct pc if (param_quirks) ohci->quirks = param_quirks; + /* TI OHCI-Lynx and compatible: set recommended configuration bits. */ + if (dev->vendor == PCI_VENDOR_ID_TI) { + pci_read_config_dword(dev, PCI_CFG_TI_LinkEnh, &link_enh); + + /* adjust latency of ATx FIFO: use 1.7 KB threshold */ + link_enh &= ~TI_LinkEnh_atx_thresh_mask; + link_enh |= TI_LinkEnh_atx_thresh_1_7K; + + /* use priority arbitration for asynchronous responses */ + link_enh |= TI_LinkEnh_enab_unfair; + + /* required for aPhyEnhanceEnable to work */ + link_enh |= TI_LinkEnh_enab_accel; + + pci_write_config_dword(dev, PCI_CFG_TI_LinkEnh, link_enh); + } + ar_context_init(&ohci->ar_request_ctx, ohci, OHCI1394_AsReqRcvContextControlSet); Index: b/drivers/firewire/ohci.h =================================================================== --- a/drivers/firewire/ohci.h +++ b/drivers/firewire/ohci.h @@ -154,4 +154,12 @@ #define OHCI1394_phy_tcode 0xe +/* TI extensions */ + +#define PCI_CFG_TI_LinkEnh 0xf4 +#define TI_LinkEnh_enab_accel 0x00000002 +#define TI_LinkEnh_enab_unfair 0x00000080 +#define TI_LinkEnh_atx_thresh_mask 0x00003000 +#define TI_LinkEnh_atx_thresh_1_7K 0x00001000 + #endif /* _FIREWIRE_OHCI_H */