We should peek mbox channels when we are left with no free
sba_requests in sba_alloc_request()

Signed-off-by: Anup Patel <anup.pa...@broadcom.com>
Reviewed-by: Ray Jui <ray....@broadcom.com>
Reviewed-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/dma/bcm-sba-raid.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/bcm-sba-raid.c b/drivers/dma/bcm-sba-raid.c
index 6d15fed..321420b 100644
--- a/drivers/dma/bcm-sba-raid.c
+++ b/drivers/dma/bcm-sba-raid.c
@@ -199,6 +199,14 @@ static inline u32 __pure sba_cmd_pq_c_mdata(u32 d, u32 b1, 
u32 b0)
 
 /* ====== General helper routines ===== */
 
+static void sba_peek_mchans(struct sba_device *sba)
+{
+       int mchan_idx;
+
+       for (mchan_idx = 0; mchan_idx < sba->mchans_count; mchan_idx++)
+               mbox_client_peek_data(sba->mchans[mchan_idx]);
+}
+
 static struct sba_request *sba_alloc_request(struct sba_device *sba)
 {
        unsigned long flags;
@@ -210,8 +218,17 @@ static struct sba_request *sba_alloc_request(struct 
sba_device *sba)
        if (req)
                list_move_tail(&req->node, &sba->reqs_alloc_list);
        spin_unlock_irqrestore(&sba->reqs_lock, flags);
-       if (!req)
+
+       if (!req) {
+               /*
+                * We have no more free requests so, we peek
+                * mailbox channels hoping few active requests
+                * would have completed which will create more
+                * room for new requests.
+                */
+               sba_peek_mchans(sba);
                return NULL;
+       }
 
        req->flags = SBA_REQUEST_STATE_ALLOCED;
        req->first = req;
@@ -558,17 +575,15 @@ static enum dma_status sba_tx_status(struct dma_chan 
*dchan,
                                     dma_cookie_t cookie,
                                     struct dma_tx_state *txstate)
 {
-       int mchan_idx;
        enum dma_status ret;
        struct sba_device *sba = to_sba_device(dchan);
 
-       for (mchan_idx = 0; mchan_idx < sba->mchans_count; mchan_idx++)
-               mbox_client_peek_data(sba->mchans[mchan_idx]);
-
        ret = dma_cookie_status(dchan, cookie, txstate);
        if (ret == DMA_COMPLETE)
                return ret;
 
+       sba_peek_mchans(sba);
+
        return dma_cookie_status(dchan, cookie, txstate);
 }
 
-- 
2.7.4

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