Commit c9747821 authored by Narsimhulu Musini's avatar Narsimhulu Musini Committed by Martin K. Petersen
Browse files

snic: Fix for missing interrupts 



- On posting an IO to the firmware, adapter generates an interrupt.
  Due to hardware issues, sometimes the adapter fails to generate
  the interrupt. This behavior skips updating transmit queue-
  counters, which in turn causes the queue full condition. The fix
  addresses the queue full condition.

- The fix also reserves a slot in transmit queue for hba reset.
  when queue full is observed during IO, there will always be room
  to post hba reset command.

Signed-off-by: default avatarNarsimhulu Musini <nmusini@cisco.com>
Signed-off-by: default avatarSesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 58fcf920

drivers/scsi/snic/snic_fwint.h

+3 −1
Original line number Diff line number Diff line
@@ -414,7 +414,7 @@ enum snic_ev_type { 
/* Payload 88 bytes = 128 - 24 - 16 */

#define SNIC_HOST_REQ_PAYLOAD	((int)(SNIC_HOST_REQ_LEN -		\

					sizeof(struct snic_io_hdr) -	\

					(2 * sizeof(u64))))

					(2 * sizeof(u64)) - sizeof(ulong)))



/*

 * snic_host_req: host -> firmware request
@@ -448,6 +448,8 @@ struct snic_host_req { 
		/* hba reset */

		struct snic_hba_reset		reset;

	} u;



	ulong req_pa;

}; /* end of snic_host_req structure */

drivers/scsi/snic/snic_io.c

+56 −6
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ snic_wq_cmpl_frame_send(struct vnic_wq *wq, 
	SNIC_TRC(snic->shost->host_no, 0, 0,

		 ((ulong)(buf->os_buf) - sizeof(struct snic_req_info)), 0, 0,

		 0);

	pci_unmap_single(snic->pdev, buf->dma_addr, buf->len, PCI_DMA_TODEVICE);



	buf->os_buf = NULL;

}
@@ -137,13 +137,36 @@ snic_select_wq(struct snic *snic) 
	return 0;

}



static int

snic_wqdesc_avail(struct snic *snic, int q_num, int req_type)

{

	int nr_wqdesc = snic->config.wq_enet_desc_count;



	if (q_num > 0) {

		/*

		 * Multi Queue case, additional care is required.

		 * Per WQ active requests need to be maintained.

		 */

		SNIC_HOST_INFO(snic->shost, "desc_avail: Multi Queue case.\n");

		SNIC_BUG_ON(q_num > 0);



		return -1;

	}



	nr_wqdesc -= atomic64_read(&snic->s_stats.fw.actv_reqs);



	return ((req_type == SNIC_REQ_HBA_RESET) ? nr_wqdesc : nr_wqdesc - 1);

}



int

snic_queue_wq_desc(struct snic *snic, void *os_buf, u16 len)

{

	dma_addr_t pa = 0;

	unsigned long flags;

	struct snic_fw_stats *fwstats = &snic->s_stats.fw;

	struct snic_host_req *req = (struct snic_host_req *) os_buf;

	long act_reqs;

	long desc_avail = 0;

	int q_num = 0;



	snic_print_desc(__func__, os_buf, len);
@@ -156,11 +179,15 @@ snic_queue_wq_desc(struct snic *snic, void *os_buf, u16 len) 
		return -ENOMEM;

	}



	req->req_pa = (ulong)pa;



	q_num = snic_select_wq(snic);



	spin_lock_irqsave(&snic->wq_lock[q_num], flags);

	if (!svnic_wq_desc_avail(snic->wq)) {

	desc_avail = snic_wqdesc_avail(snic, q_num, req->hdr.type);

	if (desc_avail <= 0) {

		pci_unmap_single(snic->pdev, pa, len, PCI_DMA_TODEVICE);

		req->req_pa = 0;

		spin_unlock_irqrestore(&snic->wq_lock[q_num], flags);

		atomic64_inc(&snic->s_stats.misc.wq_alloc_fail);

		SNIC_DBG("host = %d, WQ is Full\n", snic->shost->host_no);
@@ -169,10 +196,13 @@ snic_queue_wq_desc(struct snic *snic, void *os_buf, u16 len) 
	}



	snic_queue_wq_eth_desc(&snic->wq[q_num], os_buf, pa, len, 0, 0, 1);

	/*

	 * Update stats

	 * note: when multi queue enabled, fw actv_reqs should be per queue.

	 */

	act_reqs = atomic64_inc_return(&fwstats->actv_reqs);

	spin_unlock_irqrestore(&snic->wq_lock[q_num], flags);



	/* Update stats */

	act_reqs = atomic64_inc_return(&fwstats->actv_reqs);

	if (act_reqs > atomic64_read(&fwstats->max_actv_reqs))

		atomic64_set(&fwstats->max_actv_reqs, act_reqs);
@@ -318,11 +348,31 @@ snic_req_free(struct snic *snic, struct snic_req_info *rqi) 
		      "Req_free:rqi %p:ioreq %p:abt %p:dr %p\n",

		      rqi, rqi->req, rqi->abort_req, rqi->dr_req);



	if (rqi->abort_req)

	if (rqi->abort_req) {

		if (rqi->abort_req->req_pa)

			pci_unmap_single(snic->pdev,

					 rqi->abort_req->req_pa,

					 sizeof(struct snic_host_req),

					 PCI_DMA_TODEVICE);



		mempool_free(rqi->abort_req, snic->req_pool[SNIC_REQ_TM_CACHE]);

	}



	if (rqi->dr_req) {

		if (rqi->dr_req->req_pa)

			pci_unmap_single(snic->pdev,

					 rqi->dr_req->req_pa,

					 sizeof(struct snic_host_req),

					 PCI_DMA_TODEVICE);



	if (rqi->dr_req)

		mempool_free(rqi->dr_req, snic->req_pool[SNIC_REQ_TM_CACHE]);

	}



	if (rqi->req->req_pa)

		pci_unmap_single(snic->pdev,

				 rqi->req->req_pa,

				 rqi->req_len,

				 PCI_DMA_TODEVICE);



	mempool_free(rqi, snic->req_pool[rqi->rq_pool_type]);

}

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