From 636b1ec8575a60fb305ad6e3ede5e79d287754b6 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 3 Jan 2016 16:05:10 +1100 Subject: atari_NCR5380: Reset bus on driver initialization if required Merge the bus reset code from NCR5380.c into atari_NCR5380.c. This allows for removal of a lot of duplicated code conditional on the RESET_BOOT macro (in the next patch). The atari_NCR5380.c fork lacks the do_reset() and NCR5380_poll_politely() routines from NCR5380.c, so introduce them. They are indispensible. Keep the two implementations in sync. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Ondrej Zary Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen --- drivers/scsi/NCR5380.c | 33 ++++++++----- drivers/scsi/atari_NCR5380.c | 113 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 134 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c index 7457bd33e965..391ee8db5de1 100644 --- a/drivers/scsi/NCR5380.c +++ b/drivers/scsi/NCR5380.c @@ -838,19 +838,20 @@ static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance) case 1: case 3: case 5: - printk(KERN_INFO "scsi%d: SCSI bus busy, waiting up to five seconds\n", instance->host_no); - NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, 0, 5*HZ); + shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n"); + NCR5380_poll_politely(instance, + STATUS_REG, SR_BSY, 0, 5 * HZ); break; case 2: - printk(KERN_WARNING "scsi%d: bus busy, attempting abort\n", instance->host_no); + shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n"); do_abort(instance); break; case 4: - printk(KERN_WARNING "scsi%d: bus busy, attempting reset\n", instance->host_no); + shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n"); do_reset(instance); break; case 6: - printk(KERN_ERR "scsi%d: bus locked solid or invalid override\n", instance->host_no); + shost_printk(KERN_ERR, instance, "bus locked solid\n"); return -ENXIO; } } @@ -1579,21 +1580,29 @@ static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase } /** - * do_reset - issue a reset command - * @host: adapter to reset + * do_reset - issue a reset command + * @instance: adapter to reset * - * Issue a reset sequence to the NCR5380 and try and get the bus - * back into sane shape. + * Issue a reset sequence to the NCR5380 and try and get the bus + * back into sane shape. * - * Locks: caller holds queue lock + * This clears the reset interrupt flag because there may be no handler for + * it. When the driver is initialized, the NCR5380_intr() handler has not yet + * been installed. And when in EH we may have released the ST DMA interrupt. */ static void do_reset(struct Scsi_Host *instance) { - NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK)); + unsigned long flags; + + local_irq_save(flags); + NCR5380_write(TARGET_COMMAND_REG, + PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK)); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); - udelay(25); + udelay(50); NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG); + local_irq_restore(flags); } /* diff --git a/drivers/scsi/atari_NCR5380.c b/drivers/scsi/atari_NCR5380.c index db87ece6edb2..a15b655aa2b0 100644 --- a/drivers/scsi/atari_NCR5380.c +++ b/drivers/scsi/atari_NCR5380.c @@ -234,6 +234,9 @@ #define HOSTNO instance->host_no #define H_NO(cmd) (cmd)->device->host->host_no +static int do_abort(struct Scsi_Host *); +static void do_reset(struct Scsi_Host *); + #ifdef SUPPORT_TAGS /* @@ -475,6 +478,47 @@ static inline void initialize_SCp(struct scsi_cmnd *cmd) } } +/** + * NCR5380_poll_politely - wait for NCR5380 status bits + * @instance: controller to poll + * @reg: 5380 register to poll + * @bit: Bitmask to check + * @val: Value required to exit + * + * Polls the NCR5380 in a reasonably efficient manner waiting for + * an event to occur, after a short quick poll we begin giving the + * CPU back in non IRQ contexts + * + * Returns the value of the register or a negative error code. + */ + +static int NCR5380_poll_politely(struct Scsi_Host *instance, + int reg, int bit, int val, int t) +{ + int n = 500; + unsigned long end = jiffies + t; + int r; + + while (n-- > 0) { + r = NCR5380_read(reg); + if ((r & bit) == val) + return 0; + cpu_relax(); + } + + /* t time yet ? */ + while (time_before(jiffies, end)) { + r = NCR5380_read(reg); + if ((r & bit) == val) + return 0; + if (!in_interrupt()) + cond_resched(); + else + cpu_relax(); + } + return -ETIMEDOUT; +} + #include #if NDEBUG @@ -800,6 +844,49 @@ static int __init NCR5380_init(struct Scsi_Host *instance, int flags) return 0; } +/** + * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems. + * @instance: adapter to check + * + * If the system crashed, it may have crashed with a connected target and + * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the + * currently established nexus, which we know nothing about. Failing that + * do a bus reset. + * + * Note that a bus reset will cause the chip to assert IRQ. + * + * Returns 0 if successful, otherwise -ENXIO. + */ + +static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance) +{ + int pass; + + for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) { + switch (pass) { + case 1: + case 3: + case 5: + shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n"); + NCR5380_poll_politely(instance, + STATUS_REG, SR_BSY, 0, 5 * HZ); + break; + case 2: + shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n"); + do_abort(instance); + break; + case 4: + shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n"); + do_reset(instance); + break; + case 6: + shost_printk(KERN_ERR, instance, "bus locked solid\n"); + return -ENXIO; + } + } + return 0; +} + /** * NCR5380_exit - remove an NCR5380 * @instance: adapter to remove @@ -1741,6 +1828,32 @@ static int NCR5380_transfer_pio(struct Scsi_Host *instance, return -1; } +/** + * do_reset - issue a reset command + * @instance: adapter to reset + * + * Issue a reset sequence to the NCR5380 and try and get the bus + * back into sane shape. + * + * This clears the reset interrupt flag because there may be no handler for + * it. When the driver is initialized, the NCR5380_intr() handler has not yet + * been installed. And when in EH we may have released the ST DMA interrupt. + */ + +static void do_reset(struct Scsi_Host *instance) +{ + unsigned long flags; + + local_irq_save(flags); + NCR5380_write(TARGET_COMMAND_REG, + PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK)); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); + udelay(50); + NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); + (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG); + local_irq_restore(flags); +} + /* * Function : do_abort (Scsi_Host *host) * -- cgit v1.2.1