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atari_NCR5380: Reset bus on driver initialization if required

Browse source 
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 <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Finn Thain 2016-01-03 16:05:10 +11:00 committed by Martin K. Petersen
parent 4d8c08c71e
commit 636b1ec857
2 changed files with 134 additions and 12 deletions
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33
drivers/scsi/NCR5380.c
View file

@ -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);
}
/*

113
drivers/scsi/atari_NCR5380.c
View file

@ -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 <linux/delay.h>
#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)
*