Commit b362c0a1 authored by Brian King's avatar Brian King Committed by James Bottomley

[PATCH] SCSI Midlayer initiated START_UNIT

The ipr driver that is currently out for review talks to disk array devices
that require a START_UNIT prior to media ops, similar to normal scsi devices.
However, any time the adapter gets reset, these devices end up needing another
START_UNIT. This causes problems with the current error handling and these
devices get taken offline when this occurs. Attached is a patch which will
better handle these devices and issue a START_UNIT from the error handler
when appropriate.
parent 8ea6bc67
......@@ -37,6 +37,8 @@
#define SENSE_TIMEOUT (10*HZ)
#endif
#define START_UNIT_TIMEOUT (30*HZ)
/*
* These should *probably* be handled by the host itself.
* Since it is allowed to sleep, it probably should.
......@@ -282,6 +284,15 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
(scmd->sense_buffer[13] == 0x01)) {
return NEEDS_RETRY;
}
/*
* if the device is not started, we need to wake
* the error handler to start the motor
*/
if (scmd->device->allow_restart &&
(scmd->sense_buffer[12] == 0x04) &&
(scmd->sense_buffer[13] == 0x02)) {
return FAILED;
}
return SUCCESS;
/* these three are not supported */
......@@ -828,6 +839,105 @@ static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
return rtn;
}
/**
* scsi_eh_try_stu - Send START_UNIT to device.
* @scmd: Scsi cmd to send START_UNIT
*
* Return value:
* 0 - Device is ready. 1 - Device NOT ready.
**/
static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
{
static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
int rtn;
if (!scmd->device->allow_restart)
return 1;
memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
/*
* zero the sense buffer. the scsi spec mandates that any
* untransferred sense data should be interpreted as being zero.
*/
memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
scmd->request_buffer = NULL;
scmd->request_bufflen = 0;
scmd->use_sg = 0;
scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
scmd->underflow = 0;
scmd->sc_data_direction = DMA_NONE;
rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
/*
* when we eventually call scsi_finish, we really wish to complete
* the original request, so let's restore the original data. (db)
*/
scsi_setup_cmd_retry(scmd);
/*
* hey, we are done. let's look to see what happened.
*/
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
__FUNCTION__, scmd, rtn));
if (rtn == SUCCESS)
return 0;
return 1;
}
/**
* scsi_eh_stu - send START_UNIT if needed
* @shost: scsi host being recovered.
* @eh_done_q: list_head for processed commands.
*
* Notes:
* If commands are failing due to not ready, initializing command required,
* try revalidating the device, which will end up sending a start unit.
**/
static int scsi_eh_stu(struct Scsi_Host *shost,
struct list_head *work_q,
struct list_head *done_q)
{
struct list_head *lh, *lh_sf;
struct scsi_cmnd *scmd, *stu_scmd;
struct scsi_device *sdev;
shost_for_each_device(sdev, shost) {
stu_scmd = NULL;
list_for_each_entry(scmd, work_q, eh_entry)
if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
scsi_check_sense(scmd) == FAILED ) {
stu_scmd = scmd;
break;
}
if (!stu_scmd)
continue;
SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
" 0x%p\n", current->comm, sdev));
if (!scsi_eh_try_stu(stu_scmd)) {
if (!sdev->online || !scsi_eh_tur(stu_scmd)) {
list_for_each_safe(lh, lh_sf, work_q) {
scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
if (scmd->device == sdev)
scsi_eh_finish_cmd(scmd, done_q);
}
}
} else {
SCSI_LOG_ERROR_RECOVERY(3,
printk("%s: START_UNIT failed to sdev:"
" 0x%p\n", current->comm, sdev));
}
}
return list_empty(work_q);
}
/**
* scsi_eh_bus_device_reset - send bdr if needed
* @shost: scsi host being recovered.
......@@ -1033,7 +1143,9 @@ static int scsi_eh_host_reset(struct list_head *work_q,
if (rtn == SUCCESS) {
list_for_each_safe(lh, lh_sf, work_q) {
scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
if (!scmd->device->online || !scsi_eh_tur(scmd))
if (!scmd->device->online ||
(!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
!scsi_eh_tur(scmd))
scsi_eh_finish_cmd(scmd, done_q);
}
} else {
......@@ -1401,6 +1513,7 @@ static void scsi_eh_ready_devs(struct Scsi_Host *shost,
struct list_head *work_q,
struct list_head *done_q)
{
if (!scsi_eh_stu(shost, work_q, done_q))
if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
if (!scsi_eh_bus_reset(shost, work_q, done_q))
if (!scsi_eh_host_reset(work_q, done_q))
......
......@@ -94,6 +94,7 @@ struct scsi_device {
unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */
unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */
unsigned no_start_on_add:1; /* do not issue start on add */
unsigned allow_restart:1; /* issue START_UNIT in error handler */
unsigned int device_blocked; /* Device returned QUEUE_FULL. */
......
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