[PATCH 2.6.17-rc5-mm2 06/18] ieee1394/ohci1394: CycleTooLong interrupt management

Stefan Richter
2006-06-02T19:55:27Z

This patch modifies the ohci1394.c file to enable and manage the "cycle too
long" interrupt.
If this interrupt occurs, the "LinkControl.CycleMaster" bit of the host
controller is reseted. This implies, that the host controller does not send
"cycle start" packet anymore freezing then the isochronous communication.
The management of the interrupt added by the patch is that when the interrupt
occurs, the OHCI irq handler prints a kernel log warning and then sets the
"LinkControl.CycleMaster" bit again resuming the isochronous communication.

Signed-off-by: Jean-Baptiste Mur <jeanbaptiste@maunakeatech.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Index: linux-2.6.17-rc5-mm2/drivers/ieee1394/ohci1394.c
===================================================================
--- linux-2.6.17-rc5-mm2.orig/drivers/ieee1394/ohci1394.c 2006-06-01 20:55:39.000000000 +0200
+++ linux-2.6.17-rc5-mm2/drivers/ieee1394/ohci1394.c 2006-06-01 20:55:41.000000000 +0200
@@ -580,6 +580,7 @@ static void ohci_initialize(struct ti_oh
OHCI1394_isochRx |
OHCI1394_isochTx |
OHCI1394_postedWriteErr |
+ OHCI1394_cycleTooLong |
OHCI1394_cycleInconsistent);

/* Enable link */
@@ -2386,6 +2387,15 @@ static irqreturn_t ohci_irq_handler(int
PRINT(KERN_ERR, "physical posted write error");
/* no recovery strategy yet, had to involve protocol drivers */
}
+ if (event & OHCI1394_cycleTooLong) {
+ if(printk_ratelimit())
+ PRINT(KERN_WARNING, "isochronous cycle too long");
+ else
+ DBGMSG("OHCI1394_cycleTooLong");
+ reg_write(ohci, OHCI1394_LinkControlSet,
+ OHCI1394_LinkControl_CycleMaster);
+ event &= ~OHCI1394_cycleTooLong;
+ }
if (event & OHCI1394_cycleInconsistent) {
/* We subscribe to the cycleInconsistent event only to
* clear the corresponding event bit... otherwise,