The patch titled synclink_gt: fix per device locking has been added to the -mm tree. Its filename is synclink_gt-fix-per-device-locking.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: synclink_gt: fix per device locking From: Paul Fulghum <paulkf@xxxxxxxxxxxxx> Fix a long standing bug with per device locking. Each device has an associated spinlock for synchronizing access to hardware and state information with the ISR. A single hardware card has one or more devices. Bug: Non ISR code correctly acquires and releases the per device lock. ISR incorrectly always acquires and releases the lock of the first device on the card. The decoupled and list based nature of the ISR and deferred processing interaction allowed this to work in normal operation. Exceptional events like an application forcing hardware shutdown, reset, or reconfiguration while active can trigger the bug. Fixed ISR to acquire and release the per device lock. One exception is manipulation of the GPIO card resource which is global and effectively owned by the first device of the card. Non-ISR access to GPIO resource is changed to use lock of first device on card. Signed-off-by: Paul Fulghum <paulkf@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/char/synclink_gt.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff -puN drivers/char/synclink_gt.c~synclink_gt-fix-per-device-locking drivers/char/synclink_gt.c --- a/drivers/char/synclink_gt.c~synclink_gt-fix-per-device-locking +++ a/drivers/char/synclink_gt.c @@ -2357,26 +2357,27 @@ static irqreturn_t slgt_interrupt(int du DBGISR(("slgt_interrupt irq=%d entry\n", info->irq_level)); - spin_lock(&info->lock); - while((gsr = rd_reg32(info, GSR) & 0xffffff00)) { DBGISR(("%s gsr=%08x\n", info->device_name, gsr)); info->irq_occurred = true; for(i=0; i < info->port_count ; i++) { if (info->port_array[i] == NULL) continue; + spin_lock(&info->port_array[i]->lock); if (gsr & (BIT8 << i)) isr_serial(info->port_array[i]); if (gsr & (BIT16 << (i*2))) isr_rdma(info->port_array[i]); if (gsr & (BIT17 << (i*2))) isr_tdma(info->port_array[i]); + spin_unlock(&info->port_array[i]->lock); } } if (info->gpio_present) { unsigned int state; unsigned int changed; + spin_lock(&info->lock); while ((changed = rd_reg32(info, IOSR)) != 0) { DBGISR(("%s iosr=%08x\n", info->device_name, changed)); /* read latched state of GPIO signals */ @@ -2388,22 +2389,24 @@ static irqreturn_t slgt_interrupt(int du isr_gpio(info->port_array[i], changed, state); } } + spin_unlock(&info->lock); } for(i=0; i < info->port_count ; i++) { struct slgt_info *port = info->port_array[i]; - - if (port && (port->port.count || port->netcount) && + if (port == NULL) + continue; + spin_lock(&port->lock); + if ((port->port.count || port->netcount) && port->pending_bh && !port->bh_running && !port->bh_requested) { DBGISR(("%s bh queued\n", port->device_name)); schedule_work(&port->task); port->bh_requested = true; } + spin_unlock(&port->lock); } - spin_unlock(&info->lock); - DBGISR(("slgt_interrupt irq=%d exit\n", info->irq_level)); return IRQ_HANDLED; } @@ -2906,7 +2909,7 @@ static int set_gpio(struct slgt_info *in info->device_name, gpio.state, gpio.smask, gpio.dir, gpio.dmask)); - spin_lock_irqsave(&info->lock,flags); + spin_lock_irqsave(&info->port_array[0]->lock, flags); if (gpio.dmask) { data = rd_reg32(info, IODR); data |= gpio.dmask & gpio.dir; @@ -2919,7 +2922,7 @@ static int set_gpio(struct slgt_info *in data &= ~(gpio.smask & ~gpio.state); wr_reg32(info, IOVR, data); } - spin_unlock_irqrestore(&info->lock,flags); + spin_unlock_irqrestore(&info->port_array[0]->lock, flags); return 0; } @@ -3020,7 +3023,7 @@ static int wait_gpio(struct slgt_info *i return -EINVAL; init_cond_wait(&wait, gpio.smask); - spin_lock_irqsave(&info->lock, flags); + spin_lock_irqsave(&info->port_array[0]->lock, flags); /* enable interrupts for watched pins */ wr_reg32(info, IOER, rd_reg32(info, IOER) | gpio.smask); /* get current pin states */ @@ -3032,20 +3035,20 @@ static int wait_gpio(struct slgt_info *i } else { /* wait for target state */ add_cond_wait(&info->gpio_wait_q, &wait); - spin_unlock_irqrestore(&info->lock, flags); + spin_unlock_irqrestore(&info->port_array[0]->lock, flags); schedule(); if (signal_pending(current)) rc = -ERESTARTSYS; else gpio.state = wait.data; - spin_lock_irqsave(&info->lock, flags); + spin_lock_irqsave(&info->port_array[0]->lock, flags); remove_cond_wait(&info->gpio_wait_q, &wait); } /* disable all GPIO interrupts if no waiting processes */ if (info->gpio_wait_q == NULL) wr_reg32(info, IOER, 0); - spin_unlock_irqrestore(&info->lock,flags); + spin_unlock_irqrestore(&info->port_array[0]->lock, flags); if ((rc == 0) && copy_to_user(user_gpio, &gpio, sizeof(gpio))) rc = -EFAULT; @@ -3578,7 +3581,6 @@ static void device_init(int adapter_num, /* copy resource information from first port to others */ for (i = 1; i < port_count; ++i) { - port_array[i]->lock = port_array[0]->lock; port_array[i]->irq_level = port_array[0]->irq_level; port_array[i]->reg_addr = port_array[0]->reg_addr; alloc_dma_bufs(port_array[i]); _ Patches currently in -mm which might be from paulkf@xxxxxxxxxxxxx are synclink_gt-fix-per-device-locking.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html