| Message ID | 4D209127.5080505@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Sun, 2011-01-02 at 15:52 +0100, roel kluin wrote: > >> - if (request_irq (*irqp, NULL, IRQF_SHARED, "bogus", dev) != EBUSY) { > >> + if (request_irq (*irqp, NULL, IRQF_SHARED, "bogus", dev) != -EBUSY) { > > > This condition is completely bogus - request_irq() with a NULL handler > > now returns -EINVAL before even checking whether the IRQ is in use. The > > code should be fixed along the lines of what I did for 3c503 in commit > > b0cf4dfb7cd21556efd9a6a67edcba0840b4d98d. > > > > The e2100 and hp net drivers have the same bug. > > > > Ben. > > I've made an attempt to fix the mentioned issues, but I'm not sure it is complete. > The commit made some other changes as well which didn't seem appropriate here to me. They are absolutely necessary. In the bad old days before plug-and-play, some expansion cards would have jumpers to configure the IRQ number and no software mechanism to set or query it. Users were expected to specify the IRQ to the driver explicitly. probe_irq_{on,off}() allow drivers to avoid this by triggering an IRQ and checking which was received. That assumes that there are no IRQ conflicts, and it only works reliably in a quiescent system. These drivers have been abusing request_irq(), probe_irq_{on,off}() to do resource allocation for hardware that *does* have a software mechanism to set the IRQ number. This has become less reliable as driver loading has been made more dynamic, and is now broken completely due to the change in request_irq(). I believe the correct way to do this allocation is what I did in 3c503. Possibly it's worth adding a generic function. > And I didn't compile or run test this. I compiled but didn't have hardware to test. > As a side note, in the function changed by the commit you mentioned, el2_open(), it > appears that in current git, boolean `seen' cannot ever become true, can it? [...] The IRQ handler data is set to &seen and el2_probe_interrupt() uses that pointer to set it. Ben.
From: roel kluin <roel.kluin@gmail.com> Date: Sun, 02 Jan 2011 15:52:23 +0100 > + for (i = 0; i < ARRAY_SIZE(irqlist); i++) { > + retval = request_irq (irqlist[i], NULL, 0, "bogus", NULL); > + if (retval != -EBUSY) > + continue; > + if (retval < 0) > + goto out; > + dev->irq = irqlist[i]; > + break; This series of tests don't make much sense. If we get to the "retval < 0" check, retval must be -EBUSY. So at best it's superfluous, at worst it's confusing. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/e2100.c b/drivers/net/e2100.c index 06e72fb..115fa16 100644 --- a/drivers/net/e2100.c +++ b/drivers/net/e2100.c @@ -217,11 +217,15 @@ static int __init e21_probe1(struct net_device *dev, int ioaddr) if (dev->irq < 2) { int irqlist[] = {15, 11, 10, 12, 5, 9, 3, 4}; - for (i = 0; i < ARRAY_SIZE(irqlist); i++) - if (request_irq (irqlist[i], NULL, 0, "bogus", NULL) != -EBUSY) { - dev->irq = irqlist[i]; - break; - } + for (i = 0; i < ARRAY_SIZE(irqlist); i++) { + retval = request_irq (irqlist[i], NULL, 0, "bogus", NULL); + if (retval != -EBUSY) + continue; + if (retval < 0) + goto out; + dev->irq = irqlist[i]; + break; + } if (i >= ARRAY_SIZE(irqlist)) { printk(" unable to get IRQ %d.\n", dev->irq); retval = -EAGAIN; diff --git a/drivers/net/eepro.c b/drivers/net/eepro.c index 7c82631..24ff522 100644 --- a/drivers/net/eepro.c +++ b/drivers/net/eepro.c @@ -897,6 +897,7 @@ static int eepro_grab_irq(struct net_device *dev) { int irqlist[] = { 3, 4, 5, 7, 9, 10, 11, 12, 0 }; int *irqp = irqlist, temp_reg, ioaddr = dev->base_addr; + int retval; eepro_sw2bank1(ioaddr); /* be CAREFUL, BANK 1 now */ @@ -919,21 +920,24 @@ static int eepro_grab_irq(struct net_device *dev) outb((temp_reg & 0xf8) | irqrmap[*irqp], ioaddr + INT_NO_REG); eepro_sw2bank0(ioaddr); /* Switch back to Bank 0 */ + retval = request_irq (*irqp, NULL, IRQF_SHARED, "bogus", dev); + if (retval == -EBUSY) + continue; + if (retval < 0) + return retval; - if (request_irq (*irqp, NULL, IRQF_SHARED, "bogus", dev) != EBUSY) { - unsigned long irq_mask; - /* Twinkle the interrupt, and check if it's seen */ - irq_mask = probe_irq_on(); + unsigned long irq_mask; + /* Twinkle the interrupt, and check if it's seen */ + irq_mask = probe_irq_on(); - eepro_diag(ioaddr); /* RESET the 82595 */ - mdelay(20); + eepro_diag(ioaddr); /* RESET the 82595 */ + mdelay(20); - if (*irqp == probe_irq_off(irq_mask)) /* It's a good IRQ line */ - break; + if (*irqp == probe_irq_off(irq_mask)) /* It's a good IRQ line */ + break; - /* clear all interrupts */ - eepro_clear_int(ioaddr); - } + /* clear all interrupts */ + eepro_clear_int(ioaddr); } while (*++irqp); eepro_sw2bank1(ioaddr); /* Switch back to Bank 1 */ diff --git a/drivers/net/hp.c b/drivers/net/hp.c index d15d2f2..aeb68a0 100644 --- a/drivers/net/hp.c +++ b/drivers/net/hp.c @@ -167,17 +167,20 @@ static int __init hp_probe1(struct net_device *dev, int ioaddr) int *irqp = wordmode ? irq_16list : irq_8list; do { int irq = *irqp; - if (request_irq (irq, NULL, 0, "bogus", NULL) != -EBUSY) { - unsigned long cookie = probe_irq_on(); - /* Twinkle the interrupt, and check if it's seen. */ - outb_p(irqmap[irq] | HP_RUN, ioaddr + HP_CONFIGURE); - outb_p( 0x00 | HP_RUN, ioaddr + HP_CONFIGURE); - if (irq == probe_irq_off(cookie) /* It's a good IRQ line! */ - && request_irq (irq, eip_interrupt, 0, DRV_NAME, dev) == 0) { - printk(" selecting IRQ %d.\n", irq); - dev->irq = *irqp; - break; - } + retval = request_irq (irq, NULL, 0, "bogus", NULL); + if (retval == -EBUSY) + continue; + if (retval < 0) + goto out; + unsigned long cookie = probe_irq_on(); + /* Twinkle the interrupt, and check if it's seen. */ + outb_p(irqmap[irq] | HP_RUN, ioaddr + HP_CONFIGURE); + outb_p( 0x00 | HP_RUN, ioaddr + HP_CONFIGURE); + if (irq == probe_irq_off(cookie) /* It's a good IRQ line! */ + && request_irq (irq, eip_interrupt, 0, DRV_NAME, dev) == 0) { + printk(" selecting IRQ %d.\n", irq); + dev->irq = *irqp; + break; } } while (*++irqp); if (*irqp == 0) {