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 <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index e934713..6a27a0e 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2431,7 +2431,7 @@
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 @@
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);