firewire: ohci: fix TI TSB82AA2 regression since 2.6.35
Revert commit 54672386ccf36ffa21d1de8e75624af83f9b0eeb
"firewire: ohci: fix up configuration of TI chips".
It caused massive slow-down and data corruption with a TSB82AA2 based
StarTech EC1394B2 ExpressCard and FireWire 800 harddisks.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/657081
http://thread.gmane.org/gmane.linux.kernel.firewire.user/4013
The fact that some card EEPROMs do not program these enhancements may be
related to TSB81BA3 phy chip errata, if not to bugs of TSB82AA2 itself.
We could re-add these configuration steps, but only conditional on a
whitelist of cards on which these enhancements bring a proven positive
effect.
Reported-and-tested-by: Eric Shattow <lucent@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org> 2.6.35
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 1b05896..9dcb17d 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2840,7 +2840,7 @@
const struct pci_device_id *ent)
{
struct fw_ohci *ohci;
- u32 bus_options, max_receive, link_speed, version, link_enh;
+ u32 bus_options, max_receive, link_speed, version;
u64 guid;
int i, err, n_ir, n_it;
size_t size;
@@ -2894,23 +2894,6 @@
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);