mISDN: Add different different timer settings for hfc-pci

     - Poll-timer can now be set from 8 to 256 samples, depending on your kernel.
     - If default or 128 is used, the normal controller's clock is used as before.
       Usage: modprobe hfcpci poll=XXX
     - Added some debug code for dsp buffer size. (CMX_DELAY_DEBUG)

    Signed-off-by: Andreas Eversberg <andreas@eversberg.eu>
    Signed-off-by: Karsten Keil <kkeil@suse.de>

2 files changed, 125 insertions, 28 deletions

diff --git a/drivers/isdn/hardware/mISDN/hfc_pci.h b/drivers/isdn/hardware/mISDN/hfc_pci.h
index fd9241ab1802..3132ddc99fcd 100644
--- a/drivers/isdn/hardware/mISDN/hfc_pci.h
+++ b/drivers/isdn/hardware/mISDN/hfc_pci.h
@@ -26,7 +26,6 @@
  * change mask and threshold simultaneously
  */
 #define HFCPCI_BTRANS_THRESHOLD 128
-#define HFCPCI_BTRANS_MAX       256
 #define HFCPCI_FILLEMPTY        64
 #define HFCPCI_BTRANS_THRESMASK 0x00
 
diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c
index ea69d5862f6d..cd5d26c9909f 100644
--- a/drivers/isdn/hardware/mISDN/hfcpci.c
+++ b/drivers/isdn/hardware/mISDN/hfcpci.c
@@ -23,6 +23,25 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
+ * Module options:
+ *
+ * debug:
+ *      NOTE: only one poll value must be given for all cards
+ *      See hfc_pci.h for debug flags.
+ *
+ * poll:
+ *      NOTE: only one poll value must be given for all cards
+ *      Give the number of samples for each fifo process.
+ *      By default 128 is used. Decrease to reduce delay, increase to
+ *      reduce cpu load. If unsure, don't mess with it!
+ *      A value of 128 will use controller's interrupt. Other values will
+ *      use kernel timer, because the controller will not allow lower values
+ *      than 128.
+ *      Also note that the value depends on the kernel timer frequency.
+ *      If kernel uses a frequency of 1000 Hz, steps of 8 samples are possible.
+ *      If the kernel uses 100 Hz, steps of 80 samples are possible.
+ *      If the kernel uses 300 Hz, steps of about 26 samples are possible.
+ *
  */
 
 #include <linux/module.h>
@@ -36,10 +55,14 @@ static const char *hfcpci_revision = "2.0";
 
 static int HFC_cnt;
 static uint debug;
+static uint poll, tics;
+struct timer_list hfc_tl;
+u32     hfc_jiffies;
 
 MODULE_AUTHOR("Karsten Keil");
 MODULE_LICENSE("GPL");
 module_param(debug, uint, 0);
+module_param(poll, uint, S_IRUGO | S_IWUSR);
 
 static LIST_HEAD(HFClist);
 static DEFINE_RWLOCK(HFClock);
@@ -519,9 +542,9 @@ receive_dmsg(struct hfc_pci *hc)
 }
 
 /*
- * check for transparent receive data and read max one threshold size if avail
+ * check for transparent receive data and read max one 'poll' size if avail
  */
-static int
+static void
 hfcpci_empty_fifo_trans(struct bchannel *bch, struct bzfifo *bz, u_char *bdata)
 {
          __le16 *z1r, *z2r;
@@ -533,17 +556,19 @@ hfcpci_empty_fifo_trans(struct bchannel *bch, struct bzfifo *bz, u_char *bdata)
 
         fcnt = le16_to_cpu(*z1r) - le16_to_cpu(*z2r);
         if (!fcnt)
-                return 0;       /* no data avail */
+                return; /* no data avail */
 
         if (fcnt <= 0)
                 fcnt += B_FIFO_SIZE;    /* bytes actually buffered */
-        if (fcnt > HFCPCI_BTRANS_THRESHOLD)
-                fcnt = HFCPCI_BTRANS_THRESHOLD;         /* limit size */
-
         new_z2 = le16_to_cpu(*z2r) + fcnt;      /* new position in fifo */
         if (new_z2 >= (B_FIFO_SIZE + B_SUB_VAL))
                 new_z2 -= B_FIFO_SIZE;  /* buffer wrap */
 
+        if (fcnt > MAX_DATA_SIZE) {     /* flush, if oversized */
+                *z2r = cpu_to_le16(new_z2);             /* new position */
+                return;
+        }
+
         bch->rx_skb = mI_alloc_skb(fcnt, GFP_ATOMIC);
         if (bch->rx_skb) {
                 ptr = skb_put(bch->rx_skb, fcnt);
@@ -568,7 +593,6 @@ hfcpci_empty_fifo_trans(struct bchannel *bch, struct bzfifo *bz, u_char *bdata)
                 printk(KERN_WARNING "HFCPCI: receive out of memory\n");
 
         *z2r = cpu_to_le16(new_z2);             /* new position */
-        return 1;
 }
 
 /*
@@ -579,12 +603,11 @@ main_rec_hfcpci(struct bchannel *bch)
 {
         struct hfc_pci  *hc = bch->hw;
         int             rcnt, real_fifo;
-        int             receive, count = 5;
+        int             receive = 0, count = 5;
         struct bzfifo   *bz;
         u_char          *bdata;
         struct zt       *zp;
 
-
         if ((bch->nr & 2) && (!hc->hw.bswapped)) {
                 bz = &((union fifo_area *)(hc->hw.fifos))->b_chans.rxbz_b2;
                 bdata = ((union fifo_area *)(hc->hw.fifos))->b_chans.rxdat_b2;
@@ -624,9 +647,10 @@ Begin:
                         receive = 1;
                 else
                         receive = 0;
-        } else if (test_bit(FLG_TRANSPARENT, &bch->Flags))
-                receive = hfcpci_empty_fifo_trans(bch, bz, bdata);
-        else
+        } else if (test_bit(FLG_TRANSPARENT, &bch->Flags)) {
+                hfcpci_empty_fifo_trans(bch, bz, bdata);
+                return;
+        } else
                 receive = 0;
         if (count && receive)
                 goto Begin;
@@ -782,9 +806,9 @@ hfcpci_fill_fifo(struct bchannel *bch)
 
 next_t_frame:
                 count = bch->tx_skb->len - bch->tx_idx;
-                /* maximum fill shall be HFCPCI_BTRANS_MAX */
-                if (count > HFCPCI_BTRANS_MAX - fcnt)
-                        count = HFCPCI_BTRANS_MAX - fcnt;
+                /* maximum fill shall be poll*2 */
+                if (count > (poll << 1) - fcnt)
+                        count = (poll << 1) - fcnt;
                 if (count <= 0)
                         return;
                 /* data is suitable for fifo */
@@ -1164,37 +1188,37 @@ hfcpci_int(int intno, void *dev_id)
                 val &= ~0x80;
                 Write_hfc(hc, HFCPCI_CTMT, hc->hw.ctmt | HFCPCI_CLTIMER);
         }
-        if (val & 0x08) {
+        if (val & 0x08) {       /* B1 rx */
                 bch = Sel_BCS(hc, hc->hw.bswapped ? 2 : 1);
                 if (bch)
                         main_rec_hfcpci(bch);
                 else if (hc->dch.debug)
                         printk(KERN_DEBUG "hfcpci spurious 0x08 IRQ\n");
         }
-        if (val & 0x10) {
+        if (val & 0x10) {       /* B2 rx */
                 bch = Sel_BCS(hc, 2);
                 if (bch)
                         main_rec_hfcpci(bch);
                 else if (hc->dch.debug)
                         printk(KERN_DEBUG "hfcpci spurious 0x10 IRQ\n");
         }
-        if (val & 0x01) {
+        if (val & 0x01) {       /* B1 tx */
                 bch = Sel_BCS(hc, hc->hw.bswapped ? 2 : 1);
                 if (bch)
                         tx_birq(bch);
                 else if (hc->dch.debug)
                         printk(KERN_DEBUG "hfcpci spurious 0x01 IRQ\n");
         }
-        if (val & 0x02) {
+        if (val & 0x02) {       /* B2 tx */
                 bch = Sel_BCS(hc, 2);
                 if (bch)
                         tx_birq(bch);
                 else if (hc->dch.debug)
                         printk(KERN_DEBUG "hfcpci spurious 0x02 IRQ\n");
         }
-        if (val & 0x20)
+        if (val & 0x20)         /* D rx */
                 receive_dmsg(hc);
-        if (val & 0x04) {       /* dframe transmitted */
+        if (val & 0x04) {       /* D tx */
                 if (test_and_clear_bit(FLG_BUSY_TIMER, &hc->dch.Flags))
                         del_timer(&hc->dch.timer);
                 tx_dirq(&hc->dch);
@@ -1203,6 +1227,41 @@ hfcpci_int(int intno, void *dev_id)
         return IRQ_HANDLED;
 }
 
+static void
+hfcpci_softirq(void *arg)
+{
+        u_long          flags;
+        struct bchannel *bch;
+        struct hfc_pci  *hc;
+
+        write_lock_irqsave(&HFClock, flags);
+        list_for_each_entry(hc, &HFClist, list) {
+                if (hc->hw.int_m2 & HFCPCI_IRQ_ENABLE) {
+                        spin_lock(&hc->lock);
+                        bch = Sel_BCS(hc, hc->hw.bswapped ? 2 : 1);
+                        if (bch && bch->state == ISDN_P_B_RAW) { /* B1 rx&tx */
+                                main_rec_hfcpci(bch);
+                                tx_birq(bch);
+                        }
+                        bch = Sel_BCS(hc, hc->hw.bswapped ? 1 : 2);
+                        if (bch && bch->state == ISDN_P_B_RAW) { /* B2 rx&tx */
+                                main_rec_hfcpci(bch);
+                                tx_birq(bch);
+                        }
+                        spin_unlock(&hc->lock);
+                }
+        }
+        write_unlock_irqrestore(&HFClock, flags);
+
+        /* if next event would be in the past ... */
+        if ((s32)(hfc_jiffies + tics - jiffies) <= 0)
+                hfc_jiffies = jiffies + 1;
+        else
+                hfc_jiffies += tics;
+        hfc_tl.expires = hfc_jiffies;
+        add_timer(&hfc_tl);
+}
+
 /*
  * timer callback for D-chan busy resolution. Currently no function
  */
@@ -1312,14 +1371,16 @@ mode_hfcpci(struct bchannel *bch, int bc, int protocol)
                 }
                 if (fifo2 & 2) {
                         hc->hw.fifo_en |= HFCPCI_FIFOEN_B2;
-                        hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS +
-                            HFCPCI_INTS_B2REC);
+                        if (!tics)
+                                hc->hw.int_m1 |= (HFCPCI_INTS_B2TRANS +
+                                    HFCPCI_INTS_B2REC);
                         hc->hw.ctmt |= 2;
                         hc->hw.conn &= ~0x18;
                 } else {
                         hc->hw.fifo_en |= HFCPCI_FIFOEN_B1;
-                        hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS +
-                            HFCPCI_INTS_B1REC);
+                        if (!tics)
+                                hc->hw.int_m1 |= (HFCPCI_INTS_B1TRANS +
+                                    HFCPCI_INTS_B1REC);
                         hc->hw.ctmt |= 1;
                         hc->hw.conn &= ~0x03;
                 }
@@ -1427,7 +1488,8 @@ set_hfcpci_rxtest(struct bchannel *bch, int protocol, int chan)
                 if (chan & 2) {
                         hc->hw.sctrl_r |= SCTRL_B2_ENA;
                         hc->hw.fifo_en |= HFCPCI_FIFOEN_B2RX;
-                        hc->hw.int_m1 |= HFCPCI_INTS_B2REC;
+                        if (!tics)
+                                hc->hw.int_m1 |= HFCPCI_INTS_B2REC;
                         hc->hw.ctmt |= 2;
                         hc->hw.conn &= ~0x18;
 #ifdef REVERSE_BITORDER
@@ -1436,7 +1498,8 @@ set_hfcpci_rxtest(struct bchannel *bch, int protocol, int chan)
                 } else {
                         hc->hw.sctrl_r |= SCTRL_B1_ENA;
                         hc->hw.fifo_en |= HFCPCI_FIFOEN_B1RX;
-                        hc->hw.int_m1 |= HFCPCI_INTS_B1REC;
+                        if (!tics)
+                                hc->hw.int_m1 |= HFCPCI_INTS_B1REC;
                         hc->hw.ctmt |= 1;
                         hc->hw.conn &= ~0x03;
 #ifdef REVERSE_BITORDER
@@ -2273,7 +2336,39 @@ HFC_init(void)
 {
         int             err;
 
+        if (!poll)
+                poll = HFCPCI_BTRANS_THRESHOLD;
+
+        if (poll != HFCPCI_BTRANS_THRESHOLD) {
+                tics = poll * HZ / 8000;
+                if (tics < 1)
+                        tics = 1;
+                poll = tics * 8000 / HZ;
+                if (poll > 256 || poll < 8) {
+                        printk(KERN_ERR "%s: Wrong poll value %d not in range "
+                                "of 8..256.\n", __func__, poll);
+                        err = -EINVAL;
+                        return err;
+                }
+        }
+        if (poll != HFCPCI_BTRANS_THRESHOLD) {
+                printk(KERN_INFO "%s: Using alternative poll value of %d\n",
+                        __func__, poll);
+                hfc_tl.function = (void *)hfcpci_softirq;
+                hfc_tl.data = 0;
+                init_timer(&hfc_tl);
+                hfc_tl.expires = jiffies + tics;
+                hfc_jiffies = hfc_tl.expires;
+                add_timer(&hfc_tl);
+        } else
+                tics = 0; /* indicate the use of controller's timer */
+
         err = pci_register_driver(&hfc_driver);
+        if (err) {
+                if (timer_pending(&hfc_tl))
+                        del_timer(&hfc_tl);
+        }
+
         return err;
 }
 
@@ -2282,6 +2377,9 @@ HFC_cleanup(void)
 {
         struct hfc_pci  *card, *next;
 
+        if (timer_pending(&hfc_tl))
+                del_timer(&hfc_tl);
+
         list_for_each_entry_safe(card, next, &HFClist, list) {
                 release_card(card);
         }