Trigger an IRQ first with a test IRQ handler to find out if it really
works. Disable the IRQ if not.
This prevents hang when incorrect IRQ was specified by user.
Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/g_NCR5380.c | 44 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 41 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 09c660b..0d1f6ad 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -115,6 +115,32 @@ static int NCR5380_probe_irq(struct Scsi_Host *instance)
return irq;
}
+static bool irq_working;
+
+static irqreturn_t test_irq(int irq, void *dev_id)
+{
+ irq_working = true;
+ return IRQ_HANDLED;
+}
+
+/* test if the IRQ is working */
+static int NCR5380_test_irq(struct Scsi_Host *instance, int irq)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+
+ irq_working = false;
+ if (request_irq(irq, test_irq, 0, "NCR5380-irqtest", NULL))
+ return -EBUSY;
+ NCR5380_trigger_irq(instance);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ free_irq(irq, NULL);
+
+ if (!irq_working)
+ return -EIO;
+
+ return 0;
+}
+
/*
* Configure I/O address of 53C400A or DTC436 by writing magic numbers
* to ports 0x779 and 0x379.
@@ -323,9 +349,21 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt,
/* set IRQ for HP C2502 */
if (board == BOARD_HP_C2502)
magic_configure(port_idx, instance->irq, magic);
- if (request_irq(instance->irq, generic_NCR5380_intr,
- 0, "NCR5380", instance)) {
- printk(KERN_WARNING "scsi%d : IRQ%d not free, interrupts disabled\n", instance->host_no, instance->irq);
+ ret = NCR5380_test_irq(instance, instance->irq);
+ if (ret) {
+ printk(KERN_WARNING "scsi%d : IRQ%d not %s, interrupts disabled\n",
+ instance->host_no, instance->irq,
+ (ret == -EBUSY) ? "free" : "working");
+ instance->irq = NO_IRQ;
+ }
+ }
+
+ if (instance->irq != NO_IRQ) {
+ if (request_irq(instance->irq, generic_NCR5380_intr, 0,
+ "NCR5380", instance)) {
+ printk(KERN_WARNING "scsi%d : IRQ%d not free, interrupts disabled\n",
+ instance->host_no,
+ instance->irq);
instance->irq = NO_IRQ;
}
}
--
Ondrej Zary
--
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