From 28bdc6f6233f380ddc0b430cabd88ffeafea34c7 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Wed, 20 Sep 2006 15:59:59 +0200 Subject: [S390] cio: always query all paths on path verification. Reappearing channel paths are sometimes not utilized by CCW devices because path verification incorrectly relies on path-operational-mask information which is not updated until a channel path has been used again. Modify path verification procedure to always query all available paths to a device. Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device_pgid.c | 81 ++++++++++++++++++++++-------------------- 1 file changed, 42 insertions(+), 39 deletions(-) (limited to 'drivers/s390/cio/device_pgid.c') diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c index 1693a102dcfe..8ca2d078848c 100644 --- a/drivers/s390/cio/device_pgid.c +++ b/drivers/s390/cio/device_pgid.c @@ -245,18 +245,17 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func) memset(&cdev->private->irb, 0, sizeof(struct irb)); /* Try multiple times. */ - ret = -ENODEV; + ret = -EACCES; if (cdev->private->iretry > 0) { cdev->private->iretry--; ret = cio_start (sch, cdev->private->iccws, cdev->private->imask); - /* ret is 0, -EBUSY, -EACCES or -ENODEV */ - if ((ret != -EACCES) && (ret != -ENODEV)) + /* We expect an interrupt in case of success or busy + * indication. */ + if ((ret == 0) || (ret == -EBUSY)) return ret; } - /* PGID command failed on this path. Switch it off. */ - sch->lpm &= ~cdev->private->imask; - sch->vpm &= ~cdev->private->imask; + /* PGID command failed on this path. */ CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel " "0.%x.%04x, lpm %02X, became 'not operational'\n", cdev->private->devno, sch->schid.ssid, @@ -286,18 +285,17 @@ static int __ccw_device_do_nop(struct ccw_device *cdev) memset(&cdev->private->irb, 0, sizeof(struct irb)); /* Try multiple times. */ - ret = -ENODEV; + ret = -EACCES; if (cdev->private->iretry > 0) { cdev->private->iretry--; ret = cio_start (sch, cdev->private->iccws, cdev->private->imask); - /* ret is 0, -EBUSY, -EACCES or -ENODEV */ - if ((ret != -EACCES) && (ret != -ENODEV)) + /* We expect an interrupt in case of success or busy + * indication. */ + if ((ret == 0) || (ret == -EBUSY)) return ret; } - /* nop command failed on this path. Switch it off. */ - sch->lpm &= ~cdev->private->imask; - sch->vpm &= ~cdev->private->imask; + /* nop command failed on this path. */ CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel " "0.%x.%04x, lpm %02X, became 'not operational'\n", cdev->private->devno, sch->schid.ssid, @@ -372,27 +370,32 @@ static void __ccw_device_verify_start(struct ccw_device *cdev) { struct subchannel *sch; - __u8 imask, func; + __u8 func; int ret; sch = to_subchannel(cdev->dev.parent); - while (sch->vpm != sch->lpm) { - /* Find first unequal bit in vpm vs. lpm */ - for (imask = 0x80; imask != 0; imask >>= 1) - if ((sch->vpm & imask) != (sch->lpm & imask)) - break; - cdev->private->imask = imask; + /* Repeat for all paths. */ + for (; cdev->private->imask; cdev->private->imask >>= 1, + cdev->private->iretry = 5) { + if ((cdev->private->imask & sch->schib.pmcw.pam) == 0) + /* Path not available, try next. */ + continue; if (cdev->private->options.pgroup) { - func = (sch->vpm & imask) ? - SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH; + if (sch->opm & cdev->private->imask) + func = SPID_FUNC_ESTABLISH; + else + func = SPID_FUNC_RESIGN; ret = __ccw_device_do_pgid(cdev, func); } else ret = __ccw_device_do_nop(cdev); + /* We expect an interrupt in case of success or busy + * indication. */ if (ret == 0 || ret == -EBUSY) return; - cdev->private->iretry = 5; + /* Permanent path failure, try next. */ } - ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV); + /* Done with all paths. */ + ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV); } /* @@ -421,14 +424,14 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) else ret = __ccw_device_check_nop(cdev); memset(&cdev->private->irb, 0, sizeof(struct irb)); + switch (ret) { /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */ case 0: - /* Establish or Resign Path Group done. Update vpm. */ - if ((sch->lpm & cdev->private->imask) != 0) - sch->vpm |= cdev->private->imask; - else - sch->vpm &= ~cdev->private->imask; + /* Path verification ccw finished successfully, update lpm. */ + sch->vpm |= sch->opm & cdev->private->imask; + /* Go on with next path. */ + cdev->private->imask >>= 1; cdev->private->iretry = 5; __ccw_device_verify_start(cdev); break; @@ -441,6 +444,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) cdev->private->options.pgroup = 0; else cdev->private->flags.pgid_single = 1; + /* Retry */ + sch->vpm = 0; + cdev->private->imask = 0x80; + cdev->private->iretry = 5; /* fall through. */ case -EAGAIN: /* Try again. */ __ccw_device_verify_start(cdev); @@ -449,8 +456,7 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event) ccw_device_verify_done(cdev, -ETIME); break; case -EACCES: /* channel is not operational. */ - sch->lpm &= ~cdev->private->imask; - sch->vpm &= ~cdev->private->imask; + cdev->private->imask >>= 1; cdev->private->iretry = 5; __ccw_device_verify_start(cdev); break; @@ -463,19 +469,17 @@ ccw_device_verify_start(struct ccw_device *cdev) struct subchannel *sch = to_subchannel(cdev->dev.parent); cdev->private->flags.pgid_single = 0; + cdev->private->imask = 0x80; cdev->private->iretry = 5; - /* - * Update sch->lpm with current values to catch paths becoming - * available again. - */ + + /* Start with empty vpm. */ + sch->vpm = 0; + + /* Get current pam. */ if (stsch(sch->schid, &sch->schib)) { ccw_device_verify_done(cdev, -ENODEV); return; } - sch->lpm = sch->schib.pmcw.pim & - sch->schib.pmcw.pam & - sch->schib.pmcw.pom & - sch->opm; __ccw_device_verify_start(cdev); } @@ -524,7 +528,6 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event) switch (ret) { /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */ case 0: /* disband successful. */ - sch->vpm = 0; ccw_device_disband_done(cdev, ret); break; case -EOPNOTSUPP: -- cgit v1.2.3