scsi: aic79xx: Do not reference SCSI command when resetting device

When sending a device reset we should not take a reference to the SCSI
command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231002154328.43718-10-hare@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: hreinecke

drivers/scsi/aic7xxx/aic79xx_osm.c

@@ -536,8 +536,10 @@ ahd_linux_unmap_scb(struct ahd_softc *ahd, struct scb *scb)
 	struct scsi_cmnd *cmd;
 
 	cmd = scb->io_ctx;
-	ahd_sync_sglist(ahd, scb, BUS_DMASYNC_POSTWRITE);
-	scsi_dma_unmap(cmd);
+	if (cmd) {
+		ahd_sync_sglist(ahd, scb, BUS_DMASYNC_POSTWRITE);
+		scsi_dma_unmap(cmd);
+	}
 }
 
 /******************************** Macros **************************************/
@@ -814,7 +816,7 @@ ahd_linux_dev_reset(struct scsi_cmnd *cmd)
 
 	tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
 				    cmd->device->id, &tstate);
-	reset_scb->io_ctx = cmd;
+	reset_scb->io_ctx = NULL;
 	reset_scb->platform_data->dev = dev;
 	reset_scb->sg_count = 0;
 	ahd_set_residual(reset_scb, 0);
@@ -1769,9 +1771,16 @@ ahd_done(struct ahd_softc *ahd, struct scb *scb)
 	dev = scb->platform_data->dev;
 	dev->active--;
 	dev->openings++;
-	if ((cmd->result & (CAM_DEV_QFRZN << 16)) != 0) {
-		cmd->result &= ~(CAM_DEV_QFRZN << 16);
-		dev->qfrozen--;
+	if (cmd) {
+		if ((cmd->result & (CAM_DEV_QFRZN << 16)) != 0) {
+			cmd->result &= ~(CAM_DEV_QFRZN << 16);
+			dev->qfrozen--;
+		}
+	} else if (scb->flags & SCB_DEVICE_RESET) {
+		if (ahd->platform_data->eh_done)
+			complete(ahd->platform_data->eh_done);
+		ahd_free_scb(ahd, scb);
+		return;
 	}
 	ahd_linux_unmap_scb(ahd, scb);