[PATCH 1/2] NCR5380: Use probe_irq_*() for IRQ probing

Ondrej Zary
2016-10-30T10:50:13Z

Use standard probe_irq_on() and probe_irq_off() functions instead of own
implementation.
This prevents warning messages like this in the kernel log:
genirq: Flags mismatch irq 1. 00000000 (NCR-probe) vs. 00000080 (i8042)

Move the IRQ trigger code to a separate function so it can be used for
other purposes (testing if the IRQ works).

Also add missing IRQ reset after probe.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
---
drivers/scsi/NCR5380.c | 72 +++++++++++++++++-----------------------------
drivers/scsi/NCR5380.h | 3 +-
drivers/scsi/g_NCR5380.c | 2 +-
3 files changed, 29 insertions(+), 48 deletions(-)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index d849ffa..01c0027 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -351,50 +351,13 @@ static void NCR5380_print_phase(struct Scsi_Host *instance)
}
#endif

-
-static int probe_irq;
-
-/**
- * probe_intr - helper for IRQ autoprobe
- * @irq: interrupt number
- * @dev_id: unused
- * @regs: unused
- *
- * Set a flag to indicate the IRQ in question was received. This is
- * used by the IRQ probe code.
- */
-
-static irqreturn_t probe_intr(int irq, void *dev_id)
-{
- probe_irq = irq;
- return IRQ_HANDLED;
-}
-
-/**
- * NCR5380_probe_irq - find the IRQ of an NCR5380
- * @instance: NCR5380 controller
- * @possible: bitmask of ISA IRQ lines
- *
- * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
- * and then looking to see what interrupt actually turned up.
- */
-
-static int __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
- int possible)
+static void NCR5380_trigger_irq(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata = shost_priv(instance);
- unsigned long timeout;
- int trying_irqs, i, mask;
-
- for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1)
- if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
- trying_irqs |= mask;
-
- timeout = jiffies + msecs_to_jiffies(250);
- probe_irq = NO_IRQ;
+ unsigned long timeout = jiffies + msecs_to_jiffies(2500);

/*
- * A interrupt is triggered whenever BSY = false, SEL = true
+ * An interrupt is triggered whenever BSY = false, SEL = true
* and a bit set in the SELECT_ENABLE_REG is asserted on the
* SCSI bus.
*
@@ -402,23 +365,40 @@ static int __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
* (I/O, C/D, and MSG) match those in the TCR, so we must reset that
* to zero.
*/
-
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);

- while (probe_irq == NO_IRQ && time_before(jiffies, timeout))
+ while (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_IRQ) &&
+ time_before(jiffies, timeout))
schedule_timeout_uninterruptible(1);

NCR5380_write(SELECT_ENABLE_REG, 0);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+}

- for (i = 1, mask = 2; i < 16; ++i, mask <<= 1)
- if (trying_irqs & mask)
- free_irq(i, NULL);
+/**
+ * NCR5380_probe_irq - find the IRQ of an NCR5380
+ * @instance: NCR5380 controller
+ *
+ * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
+ * and then looking to see what interrupt actually turned up.
+ */
+
+static int NCR5380_probe_irq(struct Scsi_Host *instance)
+{
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);
+ int irqs, irq;
+
+ irqs = probe_irq_on();
+ NCR5380_trigger_irq(instance);
+ irq = probe_irq_off(irqs);
+ NCR5380_read(RESET_PARITY_INTERRUPT_REG);
+ if (irq < 0)
+ irq = 0;

- return probe_irq;
+ return irq;
}

/**
diff --git a/drivers/scsi/NCR5380.h b/drivers/scsi/NCR5380.h
index 3c6ce54..b2fca52 100644
--- a/drivers/scsi/NCR5380.h
+++ b/drivers/scsi/NCR5380.h
@@ -290,7 +290,8 @@ static inline struct scsi_cmnd *NCR5380_to_scmd(struct NCR5380_cmd *ncmd_ptr)
#define NCR5380_dprint_phase(flg, arg) do {} while (0)
#endif

-static int NCR5380_probe_irq(struct Scsi_Host *instance, int possible);
+static void NCR5380_trigger_irq(struct Scsi_Host *instance);
+static int NCR5380_probe_irq(struct Scsi_Host *instance);
static int NCR5380_init(struct Scsi_Host *instance, int flags);
static int NCR5380_maybe_reset_bus(struct Scsi_Host *);
static void NCR5380_exit(struct Scsi_Host *instance);
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 7299ad9..3790ed5 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -265,7 +265,7 @@ static int generic_NCR5380_init_one(struct scsi_host_template *tpnt,
if (irq != IRQ_AUTO)
instance->irq = irq;
else
- instance->irq = NCR5380_probe_irq(instance, 0xffff);
+ instance->irq = NCR5380_probe_irq(instance);

/* Compatibility with documented NCR5380 kernel parameters */
if (instance->irq == 255)
--
Ondrej Zary