[v2 PATCH 2/3] scsi:stex.c Add hotplug support

From: Charles Chiou
Date: Mon Feb 22 2016 - 07:04:38 EST


From: Charles <charles.chiou@xxxxxxxxxxxxxx>

1. Add hotplug support. Pegasus support surprise removal. To this end, I
use return_abnormal_state function to return DID_NO_CONNECT for all
commands which sent to driver.

2. Remove stex_hba_stop in stex_remove because we cannot send command to
device after hotplug.

3. Add new device status: MU_STATE_STOP, MU_STATE_NOCONNECT,
MU_STATE_STOP. MU_STATE_STOP is currently not referenced.
MU_STATE_NOCONNECT represent that device is plugged out from the host.

4. Use return_abnormal_function() to substitute part of code in stex_do_reset.

Signed-off-by: Charles Chiou <charles.chiou@xxxxxxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
drivers/scsi/stex.c | 53 ++++++++++++++++++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 19 deletions(-)

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 495d632..1994603 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -84,6 +84,8 @@ enum {
MU_STATE_STARTED = 2,
MU_STATE_RESETTING = 3,
MU_STATE_FAILED = 4,
+ MU_STATE_STOP = 5,
+ MU_STATE_NOCONNECT = 6,

MU_MAX_DELAY = 120,
MU_HANDSHAKE_SIGNATURE = 0x55aaaa55,
@@ -537,6 +539,27 @@ stex_ss_send_cmd(struct st_hba *hba, struct req_msg *req, u16 tag)
readl(hba->mmio_base + YH2I_REQ); /* flush */
}

+static void return_abnormal_state(struct st_hba *hba, int status)
+{
+ struct st_ccb *ccb;
+ unsigned long flags;
+ u16 tag;
+
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ for (tag = 0; tag < hba->host->can_queue; tag++) {
+ ccb = &hba->ccb[tag];
+ if (ccb->req == NULL)
+ continue;
+ ccb->req = NULL;
+ if (ccb->cmd) {
+ scsi_dma_unmap(ccb->cmd);
+ ccb->cmd->result = status << 16;
+ ccb->cmd->scsi_done(ccb->cmd);
+ ccb->cmd = NULL;
+ }
+ }
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+}
static int
stex_slave_config(struct scsi_device *sdev)
{
@@ -560,8 +583,12 @@ stex_queuecommand_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
id = cmd->device->id;
lun = cmd->device->lun;
hba = (struct st_hba *) &host->hostdata[0];
-
- if (unlikely(hba->mu_status == MU_STATE_RESETTING))
+ if (hba->mu_status == MU_STATE_NOCONNECT) {
+ cmd->result = DID_NO_CONNECT;
+ done(cmd);
+ return 0;
+ }
+ if (unlikely(hba->mu_status != MU_STATE_STARTED))
return SCSI_MLQUEUE_HOST_BUSY;

switch (cmd->cmnd[0]) {
@@ -1260,10 +1287,8 @@ static void stex_ss_reset(struct st_hba *hba)

static int stex_do_reset(struct st_hba *hba)
{
- struct st_ccb *ccb;
unsigned long flags;
unsigned int mu_status = MU_STATE_RESETTING;
- u16 tag;

spin_lock_irqsave(hba->host->host_lock, flags);
if (hba->mu_status == MU_STATE_STARTING) {
@@ -1297,20 +1322,8 @@ static int stex_do_reset(struct st_hba *hba)
else if (hba->cardtype == st_yel)
stex_ss_reset(hba);

- spin_lock_irqsave(hba->host->host_lock, flags);
- for (tag = 0; tag < hba->host->can_queue; tag++) {
- ccb = &hba->ccb[tag];
- if (ccb->req == NULL)
- continue;
- ccb->req = NULL;
- if (ccb->cmd) {
- scsi_dma_unmap(ccb->cmd);
- ccb->cmd->result = DID_RESET << 16;
- ccb->cmd->scsi_done(ccb->cmd);
- ccb->cmd = NULL;
- }
- }
- spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+ return_abnormal_state(hba, DID_RESET);

if (stex_handshake(hba) == 0)
return 0;
@@ -1771,9 +1784,11 @@ static void stex_remove(struct pci_dev *pdev)
{
struct st_hba *hba = pci_get_drvdata(pdev);

+ hba->mu_status = MU_STATE_NOCONNECT;
+ return_abnormal_state(hba, DID_NO_CONNECT);
scsi_remove_host(hba->host);

- stex_hba_stop(hba);
+ scsi_block_requests(hba->host);

stex_hba_free(hba);

--
1.9.1