Date: Mon, 11 Apr 2011 09:56:12 +0200 From: Clemens Ladisch Subject: firewire: ohci: do not start DMA contexts before link is enabled OHCI 1.1 5.7.3 not only forbids enabling or starting any DMA contexts before the linkEnable bit is set, but also explicitly warns of undefined behaviour if this order is violated. Don't violate it then. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) Index: b/drivers/firewire/ohci.c =================================================================== --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2066,8 +2066,6 @@ static int ohci_enable(struct fw_card *c reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus); reg_write(ohci, OHCI1394_LinkControlSet, - OHCI1394_LinkControl_rcvSelfID | - OHCI1394_LinkControl_rcvPhyPkt | OHCI1394_LinkControl_cycleTimerEnable | OHCI1394_LinkControl_cycleMaster); @@ -2094,9 +2092,6 @@ static int ohci_enable(struct fw_card *c reg_write(ohci, OHCI1394_FairnessControl, 0); card->priority_budget_implemented = ohci->pri_req_max != 0; - ar_context_run(&ohci->ar_request_ctx); - ar_context_run(&ohci->ar_response_ctx); - reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000); reg_write(ohci, OHCI1394_IntEventClear, ~0); reg_write(ohci, OHCI1394_IntMaskClear, ~0); @@ -2186,7 +2181,13 @@ static int ohci_enable(struct fw_card *c reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_linkEnable | OHCI1394_HCControl_BIBimageValid); - flush_writes(ohci); + + reg_write(ohci, OHCI1394_LinkControlSet, + OHCI1394_LinkControl_rcvSelfID | + OHCI1394_LinkControl_rcvPhyPkt); + + ar_context_run(&ohci->ar_request_ctx); + ar_context_run(&ohci->ar_response_ctx); /* also flushes writes */ /* We are ready to go, reset bus to finish initialization. */ fw_schedule_bus_reset(&ohci->card, false, true);