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snic: Handling control path queue issues 

Fix handles control path queue issues such as queue full and sudden
removal of hardware.

Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Narsimhulu Musini 2016-03-17 00:51:12 -07:00 committed by Martin K. Petersen
parent f352a0d5ba
commit 6e0ae74b5c
1 changed files with 30 additions and 14 deletions
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44
drivers/scsi/snic/vnic_dev.c
View File

@ -263,12 +263,20 @@ static int _svnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
int wait)
{
struct devcmd2_controller *dc2c = vdev->devcmd2;
struct devcmd2_result *result = dc2c->result + dc2c->next_result;
struct devcmd2_result *result = NULL;
unsigned int i;
int delay;
int err;
u32 posted;
u32 fetch_idx;
u32 new_posted;
u8 color;
fetch_idx = ioread32(&dc2c->wq_ctrl->fetch_index);
if (fetch_idx == 0xFFFFFFFF) { /* check for hardware gone */
/* Hardware surprise removal: return error */
return -ENODEV;
}
posted = ioread32(&dc2c->wq_ctrl->posted_index);
@ -278,6 +286,13 @@ static int _svnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
}
new_posted = (posted + 1) % DEVCMD2_RING_SIZE;
if (new_posted == fetch_idx) {
pr_err("%s: wq is full while issuing devcmd2 command %d, fetch index: %u, posted index: %u\n",
pci_name(vdev->pdev), _CMD_N(cmd), fetch_idx, posted);
return -EBUSY;
}
dc2c->cmd_ring[posted].cmd = cmd;
dc2c->cmd_ring[posted].flags = 0;
@ -299,14 +314,22 @@ static int _svnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
if (dc2c->cmd_ring[posted].flags & DEVCMD2_FNORESULT)
return 0;
result = dc2c->result + dc2c->next_result;
color = dc2c->color;
/*
* Increment next_result, after posting the devcmd, irrespective of
* devcmd result, and it should be done only once.
*/
dc2c->next_result++;
if (dc2c->next_result == dc2c->result_size) {
dc2c->next_result = 0;
dc2c->color = dc2c->color ? 0 : 1;
}
for (delay = 0; delay < wait; delay++) {
udelay(100);
if (result->color == dc2c->color) {
dc2c->next_result++;
if (dc2c->next_result == dc2c->result_size) {
dc2c->next_result = 0;
dc2c->color = dc2c->color ? 0 : 1;
}
if (result->color == color) {
if (result->error) {
err = (int) result->error;
if (err != ERR_ECMDUNKNOWN ||
@ -317,13 +340,6 @@ static int _svnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
return err;
}
if (_CMD_DIR(cmd) & _CMD_DIR_READ) {
/*
* Adding the rmb() prevents the compiler
* and/or CPU from reordering the reads which
* would potentially result in reading stale
* values.
*/
rmb();
for (i = 0; i < VNIC_DEVCMD_NARGS; i++)
vdev->args[i] = result->results[i];
}