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authorDavid Woodhouse <David.Woodhouse@intel.com>2009-01-29 06:08:27 +0300
committerDavid Woodhouse <David.Woodhouse@intel.com>2009-01-29 06:24:55 +0300
commit35c2221ba1093af77cc2164d5785a88f08a9fc57 (patch)
treebbc520759e2ebe7a7fde3efbc519376f3f607764 /drivers/atm/solos-pci.c
parentc6428e52facd03dfac971a44abca4bc058104fec (diff)
downloadlinux-35c2221ba1093af77cc2164d5785a88f08a9fc57.tar.xz
solos: Clean up handling of card->tx_mask a little
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/atm/solos-pci.c')
-rw-r--r--drivers/atm/solos-pci.c53
1 files changed, 28 insertions, 25 deletions
diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 5e228a3f7502..e7691b3328f9 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -140,7 +140,7 @@ module_param(fpga_upgrade, int, 0444);
static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
struct atm_vcc *vcc);
-static int fpga_tx(struct solos_card *);
+static uint32_t fpga_tx(struct solos_card *);
static irqreturn_t solos_irq(int irq, void *dev_id);
static struct atm_vcc* find_vcc(struct atm_dev *dev, short vpi, int vci);
static int list_vccs(int vci);
@@ -438,8 +438,6 @@ static int send_command(struct solos_card *card, int dev, const char *buf, size_
struct sk_buff *skb;
struct pkt_hdr *header;
-// dev_dbg(&card->dev->dev, "size: %d\n", size);
-
if (size > (BUF_SIZE - sizeof(*header))) {
dev_dbg(&card->dev->dev, "Command is too big. Dropping request\n");
return 0;
@@ -574,9 +572,9 @@ static irqreturn_t solos_irq(int irq, void *dev_id)
struct solos_card *card = dev_id;
int handled = 1;
- //ACK IRQ
iowrite32(0, card->config_regs + IRQ_CLEAR);
+ /* If we're up and running, just kick the tasklet to process TX/RX */
if (card->atmdev[0])
tasklet_schedule(&card->tlet);
else
@@ -588,16 +586,16 @@ static irqreturn_t solos_irq(int irq, void *dev_id)
void solos_bh(unsigned long card_arg)
{
struct solos_card *card = (void *)card_arg;
- int port;
uint32_t card_flags;
uint32_t rx_done = 0;
+ int port;
- 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 */
- if ((card_flags & card->tx_mask) != card->tx_mask)
- fpga_tx(card);
+ /*
+ * Since fpga_tx() is going to need to read the flags under its lock,
+ * it can return them to us so that we don't have to hit PCI MMIO
+ * again for the same information
+ */
+ card_flags = fpga_tx(card);
for (port = 0; port < card->nr_ports; port++) {
if (card_flags & (0x10 << port)) {
@@ -892,9 +890,8 @@ static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
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);
- if (!old_len) {
+ if (!old_len)
card->tx_mask |= (1 << port);
- }
spin_unlock_irqrestore(&card->tx_queue_lock, flags);
/* Theoretically we could just schedule the tasklet here, but
@@ -903,9 +900,9 @@ static void fpga_queue(struct solos_card *card, int port, struct sk_buff *skb,
fpga_tx(card);
}
-static int fpga_tx(struct solos_card *card)
+static uint32_t fpga_tx(struct solos_card *card)
{
- uint32_t tx_pending;
+ uint32_t tx_pending, card_flags;
uint32_t tx_started = 0;
struct sk_buff *skb;
struct atm_vcc *vcc;
@@ -913,19 +910,24 @@ static int fpga_tx(struct solos_card *card)
unsigned long flags;
spin_lock_irqsave(&card->tx_lock, flags);
-
- tx_pending = ioread32(card->config_regs + FLAGS_ADDR) & card->tx_mask;
-
- dev_vdbg(&card->dev->dev, "TX Flags are %X\n", tx_pending);
-
- for (port = 0; port < card->nr_ports; port++) {
- if (card->atmdev[port] && !(tx_pending & (1 << port))) {
+
+ card_flags = ioread32(card->config_regs + FLAGS_ADDR);
+ /*
+ * The queue lock is required for _writing_ to tx_mask, but we're
+ * OK to read it here without locking. The only potential update
+ * that we could race with is in fpga_queue() where it sets a bit
+ * for a new port... but it's going to call this function again if
+ * it's doing that, anyway.
+ */
+ tx_pending = card->tx_mask & ~card_flags;
+
+ for (port = 0; tx_pending; tx_pending >>= 1, port++) {
+ if (tx_pending & 1) {
struct sk_buff *oldskb = card->tx_skb[port];
-
if (oldskb)
pci_unmap_single(card->dev, SKB_CB(oldskb)->dma_addr,
oldskb->len, PCI_DMA_TODEVICE);
-
+
spin_lock(&card->tx_queue_lock);
skb = skb_dequeue(&card->tx_queue[port]);
if (!skb)
@@ -966,8 +968,9 @@ static int fpga_tx(struct solos_card *card)
if (tx_started)
iowrite32(tx_started, card->config_regs + FLAGS_ADDR);
+ out:
spin_unlock_irqrestore(&card->tx_lock, flags);
- return 0;
+ return card_flags;
}
static int psend(struct atm_vcc *vcc, struct sk_buff *skb)