solos: Tidy up tx_mask handling for ports which need TX

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index acba08d..bf59c40 100644 (file)
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -100,6 +100,7 @@ struct solos_card {
        void __iomem *config_regs;
        void __iomem *buffers;
        int nr_ports;
+       int tx_mask;
        struct pci_dev *dev;
        struct atm_dev *atmdev[4];
        struct tasklet_struct tlet;
@@ -590,15 +591,13 @@ void solos_bh(unsigned long card_arg)
        struct solos_card *card = (void *)card_arg;
        int port;
        uint32_t card_flags;
-       uint32_t tx_mask;
        uint32_t rx_done = 0;
 
        card_flags = ioread32(card->config_regs + FLAGS_ADDR);
 
        /* The TX bits are set if the channel is busy; clear if not. We want to
           invoke fpga_tx() unless _all_ the bits for active channels are set */
-       tx_mask = (1 << card->nr_ports) - 1;
-       if ((card_flags & tx_mask) != tx_mask)
+       if ((card_flags & card->tx_mask) != card->tx_mask)
                fpga_tx(card);
 
        for (port = 0; port < card->nr_ports; port++) {
@@ -887,15 +886,20 @@ static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
                       struct atm_vcc *vcc)
 {
        int old_len;
+       unsigned long flags;
 
        SKB_CB(skb)->vcc = vcc;
 
-       spin_lock(&card->tx_queue_lock);
+       spin_lock_irqsave(&card->tx_queue_lock, flags);
        old_len = skb_queue_len(&card->tx_queue[port]);
        skb_queue_tail(&card->tx_queue[port], skb);
-       spin_unlock(&card->tx_queue_lock);
+       if (!old_len) {
+               card->tx_mask |= (1 << port);
+       }
+       spin_unlock_irqrestore(&card->tx_queue_lock, flags);
 
-       /* If TX might need to be started, do so */
+       /* Theoretically we could just schedule the tasklet here, but
+          that introduces latency we don't want -- it's noticeable */
        if (!old_len)
                fpga_tx(card);
 }
@@ -911,7 +915,7 @@ static int fpga_tx(struct solos_card *card)
 
        spin_lock_irqsave(&card->tx_lock, flags);
 
-       tx_pending = ioread32(card->config_regs + FLAGS_ADDR);
+       tx_pending = ioread32(card->config_regs + FLAGS_ADDR) & card->tx_mask;
 
        dev_vdbg(&card->dev->dev, "TX Flags are %X\n", tx_pending);
 
@@ -925,6 +929,8 @@ static int fpga_tx(struct solos_card *card)
                        
                        spin_lock(&card->tx_queue_lock);
                        skb = skb_dequeue(&card->tx_queue[port]);
+                       if (!skb)
+                               card->tx_mask &= ~(1 << port);
                        spin_unlock(&card->tx_queue_lock);
 
                        if (skb && !card->using_dma) {