DDI_DEV_REPORT_FAULT(9F)DDI_DEV_REPORT_FAULT(9F)NAMEddi_dev_report_fault - Report a hardware failure
SYNOPSIS
#include <sys/ddi.h>
#include <sys/sunddi.h>
void ddi_dev_report_fault (dev_info_t *dip,
ddi_fault_impact_t impact, ddi_fault_location_t location,
const char *message );
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI)
PARAMETERS
dip
Pointer to the driver's dev_info structure to which the
fault report relates. (Normally the caller's own dev_info
pointer).
impact
One of a set of enumerated values indicating the impact of
the fault on the device's ability to provide normal ser‐
vice.
location
One of a set of enumerated values indicating the location
of the fault, relative to the hardware controlled by the
driver specified by dip.
message
Text of the message describing the fault being reported.
DESCRIPTION
This function provides a standardized mechanism through which device
drivers can report hardware faults. Use of this reporting mechanism
enables systems equipped with a fault management system to respond to
faults discovered by a driver. On a suitably equipped system, this
might include automatic failover to an alternative device and/or sched‐
uling replacement of the faulty hardware.
The driver must indicate the impact of the fault being reported on its
ability to provide service by passing one of the following values for
the impact parameter:
DDI_SERVICE_LOST
Indicates a total loss of service. The driver
is unable to implement the normal functions
of its hardware.
DDI_SERVICE_DEGRADED
The driver is unable to provide normal ser‐
vice, but can provide a partial or degraded
level of service. The driver may have to make
repeated attempts to perform an operation
before it succeeds, or it may be running at
less than its configured speed. A driver may
use this value to indicate that an alterna‐
tive device should be used if available, but
that it can continue operation if no alterna‐
tive exists.
DDI_SERVICE_UNAFFECTED
The service provided by the device is cur‐
rently unaffected by the reported fault. This
value may be used to report recovered errors
for predictive failure analysis.
DDI_SERVICE_RESTORED
The driver has resumed normal service, fol‐
lowing a previous report that service was
lost or degraded. This message implies that
any previously reported fault condition no
longer exists.
The location parameter should be one of the following values:
DDI_DATAPATH_FAULT
The fault lies in the datapath between the driver
and the device. The device may be unplugged, or a
problem may exist in the bus on which the device
resides. This value is appropriate if the device
is not responding to accesses, (for example, the
device may not be present) or if a call to
ddi_check_acc_handle(9F) returns DDI_FAILURE.
DDI_DEVICE_FAULT
The fault lies in the device controlled by the
driver. This value is appropriate if the device
returns an error from a selftest function, or if
the driver is able to determine that device is
present and accessible, but is not functioning
correctly.
DDI_EXTERNAL_FAULT
The fault is external to the device. For exam‐
ple, an Ethernet driver would use this value when
reporting a cable fault.
If a device returns detectably bad data during
normal operation (an "impossible" value in a reg‐
ister or DMA status area, for example), the
driver should check the associated handle using
ddi_check_acc_handle(9F) or ddi_check_dma_han‐
dle(9F) before reporting the fault. If the fault
is associated with the handle, the driver should
specify DDI_DATAPATH_FAULT rather than
DDI_DEVICE_FAULT. As a consequence of this call,
the device's state may be updated to reflect the
level of service currently available. See
ddi_get_devstate(9F).
Note that if a driver calls ddi_get_devstate(9F)
and discovers that its device is down, a fault
should not be reported- the device is down as the
result of a fault that has already been reported.
Additionally, a driver should avoid incurring or
reporting additional faults when the device is
already known to be unusable. The
ddi_dev_report_fault() call should only be used
to report hardware (device) problems and should
not be used to report purely software problems
such as memory (or other resource) exhaustion.
EXAMPLES
An Ethernet driver receives an error interrupt from its device if vari‐
ous fault conditions occur. The driver must read an error status reg‐
ister to determine the nature of the fault, and report it appropri‐
ately:
static int
xx_error_intr(xx_soft_state *ssp)
{
...
error_status = ddi_get32(ssp->handle, &ssp->regs->xx_err_status);
if (ddi_check_acc_handle(ssp->handle) != DDI_SUCCESS) {
ddi_dev_report_fault(ssp->dip, DDI_SERVICE_LOST,
DDI_DATAPATH_FAULT, "register access fault");
return DDI_INTR_UNCLAIMED;
}
if (ssp->error_status & XX_CABLE_FAULT) {
ddi_dev_report_fault(ssp->dip, DDI_SERVICE_LOST,
DDI_EXTERNAL_FAULT, "cable fault")
return DDI_INTR_CLAIMED;
}
if (ssp->error_status & XX_JABBER) {
ddi_dev_report_fault(ssp->dip, DDI_SERVICE_DEGRADED,
DDI_EXTERNAL_FAULT, "jabbering detected")
return DDI_INTR_CLAIMED;
}
...
}
CONTEXT
The ddi_dev_report_fault() function may be called from user, kernel, or
interrupt context.
SEE ALSOddi_check_acc_handle(9F), ddi_check_dma_handle(9F), ddi_get_devs‐
tate(9F)
Aug 13, 1999 DDI_DEV_REPORT_FAULT(9F)
