[PATCH 43/47] fas216: Rework device reset to not rely on SCSI command pointer

Hannes Reinecke
2017-06-28T08:33:41Z

The device reset code should not rely on the SCSI command pointer;
it will be going away with the device reset handler rework.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/arm/fas216.c | 51 +++++++++++++++++++++++------------------------
1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/drivers/scsi/arm/fas216.c b/drivers/scsi/arm/fas216.c
index c93ad3a..e3ff1c3 100644
--- a/drivers/scsi/arm/fas216.c
+++ b/drivers/scsi/arm/fas216.c
@@ -1985,8 +1985,7 @@ static void fas216_devicereset_done(FAS216_Info *info, struct scsi_cmnd *SCpnt,
{
fas216_log(info, LOG_ERROR, "fas216 device reset complete");

- info->rstSCpnt = NULL;
- info->rst_dev_status = 1;
+ info->rst_dev_status = 0;
wake_up(&info->eh_wait);
}

@@ -2139,12 +2138,12 @@ static void fas216_done(FAS216_Info *info, unsigned int result)

fas216_checkmagic(info);

- if (!info->SCpnt)
+ if (!info->SCpnt && !info->rst_dev_status)
goto no_command;

SCpnt = info->SCpnt;
info->SCpnt = NULL;
- info->scsi.phase = PHASE_IDLE;
+ info->scsi.phase = PHASE_IDLE;

if (info->scsi.aborting) {
fas216_log(info, 0, "uncaught abort - returning DID_ABORT");
@@ -2156,7 +2155,7 @@ static void fas216_done(FAS216_Info *info, unsigned int result)
* Sanity check the completion - if we have zero bytes left
* to transfer, we should not have a valid pointer.
*/
- if (info->scsi.SCp.ptr && info->scsi.SCp.this_residual == 0) {
+ if (SCpnt && info->scsi.SCp.ptr && info->scsi.SCp.this_residual == 0) {
scmd_printk(KERN_INFO, SCpnt,
"zero bytes left to transfer, but buffer pointer still valid: ptr=%p len=%08x\n",
info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
@@ -2169,12 +2168,18 @@ static void fas216_done(FAS216_Info *info, unsigned int result)
* the sense information, fas216_kick will re-assert the busy
* status.
*/
- info->device[SCpnt->device->id].parity_check = 0;
- clear_bit(SCpnt->device->id * 8 +
- (u8)(SCpnt->device->lun & 0x7), info->busyluns);
-
- fn = (void (*)(FAS216_Info *, struct scsi_cmnd *, unsigned int))SCpnt->host_scribble;
- fn(info, SCpnt, result);
+ if (SCpnt) {
+ info->device[SCpnt->device->id].parity_check = 0;
+ clear_bit(SCpnt->device->id * 8 +
+ (u8)(SCpnt->device->lun & 0x7), info->busyluns);
+ }
+ if (info->rst_dev_status) {
+ info->rst_dev_status = 0;
+ wake_up(&info->eh_wait);
+ } else {
+ fn = (void (*)(FAS216_Info *, struct scsi_cmnd *, unsigned int))SCpnt->host_scribble;
+ fn(info, SCpnt, result);
+ }

if (info->scsi.irq) {
spin_lock_irqsave(&info->host_lock, flags);
@@ -2326,9 +2331,9 @@ static void fas216_eh_timer(unsigned long data)

del_timer(&info->eh_timer);

- if (info->rst_bus_status == 0)
+ if (info->rst_bus_status == 1)
info->rst_bus_status = -1;
- if (info->rst_dev_status == 0)
+ if (info->rst_dev_status == 1)
info->rst_dev_status = -1;

wake_up(&info->eh_wait);
@@ -2471,9 +2476,10 @@ int fas216_eh_abort(struct scsi_cmnd *SCpnt)
*/
int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
{
- FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
+ struct scsi_device *sdev = SCpnt->device;
+ FAS216_Info *info = (FAS216_Info *)sdev->host->hostdata;
unsigned long flags;
- int i, res = FAILED, target = SCpnt->device->id;
+ int i, res = FAILED, target = sdev->id;

fas216_log(info, LOG_ERROR, "device reset for target %d", target);

@@ -2487,7 +2493,7 @@ int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
* and we need a bus reset.
*/
if (info->SCpnt && !info->scsi.disconnectable &&
- info->SCpnt->device->id == SCpnt->device->id)
+ info->SCpnt->device->id == sdev->id)
break;

/*
@@ -2505,14 +2511,7 @@ int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
for (i = 0; i < 8; i++)
clear_bit(target * 8 + i, info->busyluns);

- /*
- * Hijack this SCSI command structure to send
- * a bus device reset message to this device.
- */
- SCpnt->host_scribble = (void *)fas216_devicereset_done;
-
- info->rst_dev_status = 0;
- info->rstSCpnt = SCpnt;
+ info->rst_dev_status = 1;

if (info->scsi.phase == PHASE_IDLE)
fas216_kick(info);
@@ -2523,13 +2522,13 @@ int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
/*
* Wait up to 30 seconds for the reset to complete.
*/
- wait_event(info->eh_wait, info->rst_dev_status);
+ wait_event(info->eh_wait, info->rst_dev_status <= 0);

del_timer_sync(&info->eh_timer);
spin_lock_irqsave(&info->host_lock, flags);
info->rstSCpnt = NULL;

- if (info->rst_dev_status == 1)
+ if (info->rst_dev_status == 0)
res = SUCCESS;
} while (0);

--
1.8.5.6