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Commit ecf8328e authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter
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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: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 115881d3

drivers/firewire/ohci.c

+7 −6
Original line number Diff line number Diff line
@@ -2066,8 +2066,6 @@ static int ohci_enable(struct fw_card *card, 


	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 *card, 
	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 *card, 
	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);