SCSI bus protocol sometimes requires monitoring two related conditions simultaneously. Enhance NCR5380_poll_politely() for this purpose, and put it to use in the arbitration algorithm. It will also find use in pseudo DMA. Signed-off-by: Finn Thain --- drivers/scsi/NCR5380.c | 66 ++++++++++++++++++++++++------------------- drivers/scsi/atari_NCR5380.c | 62 ++++++++++++++++++++++++---------------- 2 files changed, 75 insertions(+), 53 deletions(-) Index: linux/drivers/scsi/atari_NCR5380.c =================================================================== --- linux.orig/drivers/scsi/atari_NCR5380.c 2015-12-22 12:16:28.000000000 +1100 +++ linux/drivers/scsi/atari_NCR5380.c 2015-12-22 12:16:30.000000000 +1100 @@ -457,11 +457,14 @@ static inline void initialize_SCp(struct } /** - * NCR5380_poll_politely - wait for chip register value + * NCR5380_poll_politely2 - wait for two chip register values * @instance: controller to poll - * @reg: 5380 register to poll - * @bit: Bitmask to check - * @val: Value required to exit + * @reg1: 5380 register to poll + * @bit1: Bitmask to check + * @val1: Expected value + * @reg2: Second 5380 register to poll + * @bit2: Second bitmask to check + * @val2: Second expected value * @wait: Time-out in jiffies * * Polls the chip in a reasonably efficient manner waiting for an @@ -469,11 +472,12 @@ static inline void initialize_SCp(struct * (if possible). In irq contexts the time-out is arbitrarily limited. * Callers may hold locks as long as they are held in irq mode. * - * Returns 0 if event occurred otherwise -ETIMEDOUT. + * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT. */ -static int NCR5380_poll_politely(struct Scsi_Host *instance, - int reg, int bit, int val, int wait) +static int NCR5380_poll_politely2(struct Scsi_Host *instance, + int reg1, int bit1, int val1, + int reg2, int bit2, int val2, int wait) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned long deadline = jiffies + wait; @@ -482,9 +486,11 @@ static int NCR5380_poll_politely(struct /* Busy-wait for up to 10 ms */ n = min(10000U, jiffies_to_usecs(wait)); n *= hostdata->accesses_per_ms; - n /= 1000; + n /= 2000; do { - if ((NCR5380_read(reg) & bit) == val) + if ((NCR5380_read(reg1) & bit1) == val1) + return 0; + if ((NCR5380_read(reg2) & bit2) == val2) return 0; cpu_relax(); } while (n--); @@ -495,13 +501,22 @@ static int NCR5380_poll_politely(struct /* Repeatedly sleep for 1 ms until deadline */ while (time_is_after_jiffies(deadline)) { schedule_timeout_uninterruptible(1); - if ((NCR5380_read(reg) & bit) == val) + if ((NCR5380_read(reg1) & bit1) == val1) + return 0; + if ((NCR5380_read(reg2) & bit2) == val2) return 0; } return -ETIMEDOUT; } +static inline int NCR5380_poll_politely(struct Scsi_Host *instance, + int reg, int bit, int val, int wait) +{ + return NCR5380_poll_politely2(instance, reg, bit, val, + reg, bit, val, wait); +} + #include #if NDEBUG @@ -1348,7 +1363,6 @@ static int NCR5380_select(struct Scsi_Ho int len; int err; unsigned long flags; - unsigned long timeout; NCR5380_dprint(NDEBUG_ARBITRATION, instance); dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO, @@ -1378,20 +1392,18 @@ static int NCR5380_select(struct Scsi_Ho */ local_irq_restore(flags); - timeout = jiffies + HZ; - while (1) { - if (time_is_before_jiffies(timeout)) { - NCR5380_write(MODE_REG, MR_BASE); - shost_printk(KERN_ERR, instance, - "select: arbitration timeout\n"); - return -1; - } - if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) { - /* Reselection interrupt */ - return -1; - } - if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) - break; + err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0, + INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, + ICR_ARBITRATION_PROGRESS, HZ); + if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) { + /* Reselection interrupt */ + return -1; + } + if (err < 0) { + NCR5380_write(MODE_REG, MR_BASE); + shost_printk(KERN_ERR, instance, + "select: arbitration timeout\n"); + return -1; } /* The SCSI-2 arbitration delay is 2.4 us */ Index: linux/drivers/scsi/NCR5380.c =================================================================== --- linux.orig/drivers/scsi/NCR5380.c 2015-12-22 12:16:28.000000000 +1100 +++ linux/drivers/scsi/NCR5380.c 2015-12-22 12:16:30.000000000 +1100 @@ -262,11 +262,14 @@ static inline void initialize_SCp(struct } /** - * NCR5380_poll_politely - wait for chip register value + * NCR5380_poll_politely2 - wait for two chip register values * @instance: controller to poll - * @reg: 5380 register to poll - * @bit: Bitmask to check - * @val: Value required to exit + * @reg1: 5380 register to poll + * @bit1: Bitmask to check + * @val1: Expected value + * @reg2: Second 5380 register to poll + * @bit2: Second bitmask to check + * @val2: Second expected value * @wait: Time-out in jiffies * * Polls the chip in a reasonably efficient manner waiting for an @@ -274,11 +277,12 @@ static inline void initialize_SCp(struct * (if possible). In irq contexts the time-out is arbitrarily limited. * Callers may hold locks as long as they are held in irq mode. * - * Returns 0 if event occurred otherwise -ETIMEDOUT. + * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT. */ -static int NCR5380_poll_politely(struct Scsi_Host *instance, - int reg, int bit, int val, int wait) +static int NCR5380_poll_politely2(struct Scsi_Host *instance, + int reg1, int bit1, int val1, + int reg2, int bit2, int val2, int wait) { struct NCR5380_hostdata *hostdata = shost_priv(instance); unsigned long deadline = jiffies + wait; @@ -287,9 +291,11 @@ static int NCR5380_poll_politely(struct /* Busy-wait for up to 10 ms */ n = min(10000U, jiffies_to_usecs(wait)); n *= hostdata->accesses_per_ms; - n /= 1000; + n /= 2000; do { - if ((NCR5380_read(reg) & bit) == val) + if ((NCR5380_read(reg1) & bit1) == val1) + return 0; + if ((NCR5380_read(reg2) & bit2) == val2) return 0; cpu_relax(); } while (n--); @@ -300,13 +306,22 @@ static int NCR5380_poll_politely(struct /* Repeatedly sleep for 1 ms until deadline */ while (time_is_after_jiffies(deadline)) { schedule_timeout_uninterruptible(1); - if ((NCR5380_read(reg) & bit) == val) + if ((NCR5380_read(reg1) & bit1) == val1) + return 0; + if ((NCR5380_read(reg2) & bit2) == val2) return 0; } return -ETIMEDOUT; } +static inline int NCR5380_poll_politely(struct Scsi_Host *instance, + int reg, int bit, int val, int wait) +{ + return NCR5380_poll_politely2(instance, reg, bit, val, + reg, bit, val, wait); +} + static struct { unsigned char value; const char *name; @@ -1101,7 +1116,6 @@ static int NCR5380_select(struct Scsi_Ho unsigned char *data; int len; int err; - unsigned long timeout; NCR5380_dprint(NDEBUG_ARBITRATION, instance); dprintk(NDEBUG_ARBITRATION, "scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id); @@ -1125,23 +1139,19 @@ static int NCR5380_select(struct Scsi_Ho */ spin_unlock_irq(instance->host_lock); - timeout = jiffies + HZ; - while (1) { - if (time_is_before_jiffies(timeout)) { - NCR5380_write(MODE_REG, MR_BASE); - shost_printk(KERN_ERR, instance, - "select: arbitration timeout\n"); - spin_lock_irq(instance->host_lock); - return -1; - } - spin_lock_irq(instance->host_lock); - if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) { - /* Reselection interrupt */ - return -1; - } - if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) - break; - spin_unlock_irq(instance->host_lock); + err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0, + INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS, + ICR_ARBITRATION_PROGRESS, HZ); + spin_lock_irq(instance->host_lock); + if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) { + /* Reselection interrupt */ + return -1; + } + if (err < 0) { + NCR5380_write(MODE_REG, MR_BASE); + shost_printk(KERN_ERR, instance, + "select: arbitration timeout\n"); + return -1; } /* The SCSI-2 arbitration delay is 2.4 us */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/