[PATCH] Fix SMP support on 3c527 net driver

From: Felipe W Damasio (felipewd_at_terra.com.br)
Date: 08/31/03

  • Next message: viro_at_parcelfarce.linux.theplanet.co.uk: "Re: [PATCH] vmalloc might sleep" 
    Date:	Sun, 31 Aug 2003 00:06:02 -0300
To: rnp@netlink.co.nz

            Hi Richard,

            Patch against 2.6.0-test4

            This is a first try to fix SMP support on the 3c527 net driver, by
    removing cli/sti and replacing them with proper locking.

            Since the critical section that used cli/save_flags to serialize its
    access had "sleep_on" in it, I added a per-device semaphore to it, and
    used this lock instead. Also, the down/up function doesn't seem to be
    used in interrupt context, so I think it will work.

            Compile fine, but I don't have the hardware to test it.

            Please review this patch and consider applying if it looks good,

            Thanks.

    Felipe 

    -- 
It's most certainly GNU/Linux, not Linux. Read more at
http://www.gnu.org/gnu/why-gnu-linux.html

    --- linux-2.6.0-test4/drivers/net/3c527.c Fri Aug 22 20:56:34 2003
    +++ linux-2.6.0-test4-fwd/drivers/net/3c527.c Sat Aug 30 23:57:25 2003
    @@ -17,8 +17,8 @@
      */
     
     #define DRV_NAME "3c527"
    -#define DRV_VERSION "0.6a"
    -#define DRV_RELDATE "2001/11/17"
    +#define DRV_VERSION "0.6b"
    +#define DRV_RELDATE "2003/08/31"
     
     static const char *version =
     DRV_NAME ".c:v" DRV_VERSION " " DRV_RELDATE " Richard Proctor (rnp@netlink.co.nz)\n";
    @@ -174,6 +174,8 @@
     
             struct mc32_ring_desc tx_ring[TX_RING_LEN]; /* Host Transmit ring */
             struct mc32_ring_desc rx_ring[RX_RING_LEN]; /* Host Receive ring */
    +
    + struct semaphore mc32_sem;
     
             u16 tx_ring_tail; /* index to tx de-queue end */
             u16 tx_ring_head; /* index to tx en-queue end */
    @@ -615,16 +617,14 @@
     {
             struct mc32_local *lp = (struct mc32_local *)dev->priv;
             int ioaddr = dev->base_addr;
    - unsigned long flags;
             int ret = 0;
             
             /*
              * Wait for a command
              */
              
    - save_flags(flags);
    - cli();
    -
    + down(&lp->mc32_sem);
    +
             while(lp->exec_pending)
                     sleep_on(&lp->event);
                     
    @@ -634,7 +634,7 @@
     
             lp->exec_pending=1;
             
    - restore_flags(flags);
    + up(&lp->mc32_sem);
             
             lp->exec_box->mbox=0;
             lp->exec_box->mbox=cmd;
    @@ -645,13 +645,12 @@
             while(!(inb(ioaddr+HOST_STATUS)&HOST_STATUS_CRR));
             outb(1<<6, ioaddr+HOST_CMD);
     
    - save_flags(flags);
    - cli();
    + down(&lp->mc32_sem);
     
             while(lp->exec_pending!=2)
                     sleep_on(&lp->event);
             lp->exec_pending=0;
    - restore_flags(flags);
    + up(&lp->mc32_sem);
             
             if(lp->exec_box->mbox&(1<<13))
                     ret = -1;
    @@ -725,7 +724,6 @@
     {
             struct mc32_local *lp = (struct mc32_local *)dev->priv;
             int ioaddr = dev->base_addr;
    - unsigned long flags;
     
             mc32_ready_poll(dev);
     
    @@ -735,14 +733,13 @@
             outb(HOST_CMD_SUSPND_RX, ioaddr+HOST_CMD);
             mc32_ready_poll(dev);
             outb(HOST_CMD_SUSPND_TX, ioaddr+HOST_CMD);
    -
    - save_flags(flags);
    - cli();
    +
    + down(&lp->mc32_sem);
                     
             while(lp->xceiver_state!=HALTED)
                     sleep_on(&lp->event);
                     
    - restore_flags(flags);
    + up(&lp->mc32_sem);
     }
     
     
    @@ -1008,6 +1005,7 @@
                     return -ENOBUFS;
             }
     
    + init_MUTEX(&lp->mc32_sem);
             lp->desired_state = RUNNING;
             
             /* And finally, set the ball rolling... */
    @@ -1056,18 +1054,16 @@
     static int mc32_send_packet(struct sk_buff *skb, struct net_device *dev)
     {
             struct mc32_local *lp = (struct mc32_local *)dev->priv;
    - unsigned long flags;
     
             volatile struct skb_header *p, *np;
     
             netif_stop_queue(dev);
     
    - save_flags(flags);
    - cli();
    + down(&lp->mc32_sem);
                     
             if(atomic_read(&lp->tx_count)==0)
             {
    - restore_flags(flags);
    + up(&lp->mc32_sem);
                     return 1;
             }
     
    @@ -1098,7 +1094,7 @@
                     
             p->control &= ~CONTROL_EOL; /* Clear EOL on p */
     out:
    - restore_flags(flags);
    + up(&lp->mc32_sem);
     
             netif_wake_queue(dev);
             return 0;

    -
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