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Commit ab69b3cf authored by John Gregor's avatar John Gregor Committed by Roland Dreier
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IB/ipath: Fix SDMA error recovery in absence of link status change 



What's fixed:

    in ipath_cancel_sends()

        We need to unconditionally set ABORTING.  So, swap the tests
        so the set_bit() isn't shadowed by the &&.

        If we've disarmed the piobufs, then we need to unconditionally
        set DISARMED.  So, move it out from the overly protective if
        at the bottom.

    in sdma_abort_task()

        Abort_task was written knowing that the SDMA engine would always
        be reset (and restarted) on error.  A recent change broke that
        fundamental assumption by taking the restart portion and making
        it conditional on a link status change.  But, SDMA can go boom
        without a link status change in some conditions.

Signed-off-by: default avatarJohn Gregor <john.gregor@qlogic.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent e2ab41ca

drivers/infiniband/hw/ipath/ipath_driver.c

+5 −3
Original line number Diff line number Diff line
@@ -1898,8 +1898,8 @@ void ipath_cancel_sends(struct ipath_devdata *dd, int restore_sendctrl) 


		spin_lock_irqsave(&dd->ipath_sdma_lock, flags);

		skip_cancel =

			!test_bit(IPATH_SDMA_DISABLED, statp) &&

			test_and_set_bit(IPATH_SDMA_ABORTING, statp);

			test_and_set_bit(IPATH_SDMA_ABORTING, statp)

			&& !test_bit(IPATH_SDMA_DISABLED, statp);

		spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);

		if (skip_cancel)

			goto bail;
@@ -1930,6 +1930,9 @@ void ipath_cancel_sends(struct ipath_devdata *dd, int restore_sendctrl) 
	ipath_disarm_piobufs(dd, 0,

		dd->ipath_piobcnt2k + dd->ipath_piobcnt4k);



	if (dd->ipath_flags & IPATH_HAS_SEND_DMA)

		set_bit(IPATH_SDMA_DISARMED, &dd->ipath_sdma_status);



	if (restore_sendctrl) {

		/* else done by caller later if needed */

		spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);
@@ -1949,7 +1952,6 @@ void ipath_cancel_sends(struct ipath_devdata *dd, int restore_sendctrl) 
		/* only wait so long for intr */

		dd->ipath_sdma_abort_intr_timeout = jiffies + HZ;

		dd->ipath_sdma_reset_wait = 200;

		__set_bit(IPATH_SDMA_DISARMED, &dd->ipath_sdma_status);

		if (!test_bit(IPATH_SDMA_SHUTDOWN, &dd->ipath_sdma_status))

			tasklet_hi_schedule(&dd->ipath_sdma_abort_task);

		spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);

drivers/infiniband/hw/ipath/ipath_sdma.c

+24 −7
Original line number Diff line number Diff line
@@ -308,13 +308,15 @@ static void sdma_abort_task(unsigned long opaque) 
		spin_unlock_irqrestore(&dd->ipath_sdma_lock, flags);



		/*

		 * Don't restart sdma here. Wait until link is up to ACTIVE.

		 * VL15 MADs used to bring the link up use PIO, and multiple

		 * link transitions otherwise cause the sdma engine to be

		 * Don't restart sdma here (with the exception

		 * below). Wait until link is up to ACTIVE.  VL15 MADs

		 * used to bring the link up use PIO, and multiple link

		 * transitions otherwise cause the sdma engine to be

		 * stopped and started multiple times.

		 * The disable is done here, including the shadow, so the

		 * state is kept consistent.

		 * See ipath_restart_sdma() for the actual starting of sdma.

		 * The disable is done here, including the shadow,

		 * so the state is kept consistent.

		 * See ipath_restart_sdma() for the actual starting

		 * of sdma.

		 */

		spin_lock_irqsave(&dd->ipath_sendctrl_lock, flags);

		dd->ipath_sendctrl &= ~INFINIPATH_S_SDMAENABLE;
@@ -326,6 +328,13 @@ static void sdma_abort_task(unsigned long opaque) 
		/* make sure I see next message */

		dd->ipath_sdma_abort_jiffies = 0;



		/*

		 * Not everything that takes SDMA offline is a link

		 * status change.  If the link was up, restart SDMA.

		 */

		if (dd->ipath_flags & IPATH_LINKACTIVE)

			ipath_restart_sdma(dd);



		goto done;

	}
@@ -427,7 +436,12 @@ int setup_sdma(struct ipath_devdata *dd) 
		goto done;

	}



	dd->ipath_sdma_status = 0;

	/*

	 * Set initial status as if we had been up, then gone down.

	 * This lets initial start on transition to ACTIVE be the

	 * same as restart after link flap.

	 */

	dd->ipath_sdma_status = IPATH_SDMA_ABORT_ABORTED;

	dd->ipath_sdma_abort_jiffies = 0;

	dd->ipath_sdma_generation = 0;

	dd->ipath_sdma_descq_tail = 0;
@@ -618,6 +632,9 @@ void ipath_restart_sdma(struct ipath_devdata *dd) 
	ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);

	spin_unlock_irqrestore(&dd->ipath_sendctrl_lock, flags);



	/* notify upper layers */

	ipath_ib_piobufavail(dd->verbs_dev);



bail:

	return;

}