recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.9/0065-can-sja1000-fix-isr-hang-when-hw-is-unplugged-under-.patch

   1 From 9bda01cc81b40639565e63223d7c5413bb15b99a Mon Sep 17 00:00:00 2001
   2 From: Oliver Hartkopp <socketcan@hartkopp.net>
   3 Date: Wed, 15 Feb 2012 17:51:56 +0100
   4 Subject: [PATCH 65/73] can: sja1000: fix isr hang when hw is unplugged under
   5  load
   6
   7 commit a7762b10c12a70c5dbf2253142764b728ac88c3a upstream.
   8
   9 In the case of hotplug enabled devices (PCMCIA/PCIeC) the removal of the
  10 hardware can cause an infinite loop in the common sja1000 isr.
  11
  12 Use the already retrieved status register to indicate a possible hardware
  13 removal and double check by reading the mode register in sja1000_is_absent.
  14
  15 Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
  16 Acked-by: Wolfgang Grandegger <wg@grandegger.com>
  17 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19 ---
  20  drivers/net/can/sja1000/sja1000.c |   13 ++++++++++++-
  21  1 files changed, 12 insertions(+), 1 deletions(-)
  22
  23 diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
  24 index 04a3f1b..192b0d1 100644
  25 --- a/drivers/net/can/sja1000/sja1000.c
  26 +++ b/drivers/net/can/sja1000/sja1000.c
  27 @@ -95,11 +95,16 @@ static void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
  28         spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
  29  }
  30
  31 +static int sja1000_is_absent(struct sja1000_priv *priv)
  32 +{
  33 +       return (priv->read_reg(priv, REG_MOD) == 0xFF);
  34 +}
  35 +
  36  static int sja1000_probe_chip(struct net_device *dev)
  37  {
  38         struct sja1000_priv *priv = netdev_priv(dev);
  39
  40 -       if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
  41 +       if (priv->reg_base && sja1000_is_absent(priv)) {
  42                 printk(KERN_INFO "%s: probing @0x%lX failed\n",
  43                        DRV_NAME, dev->base_addr);
  44                 return 0;
  45 @@ -493,6 +498,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
  46         while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
  47                 n++;
  48                 status = priv->read_reg(priv, REG_SR);
  49 +               /* check for absent controller due to hw unplug */
  50 +               if (status == 0xFF && sja1000_is_absent(priv))
  51 +                       return IRQ_NONE;
  52
  53                 if (isrc & IRQ_WUI)
  54                         dev_warn(dev->dev.parent, "wakeup interrupt\n");
  55 @@ -509,6 +517,9 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
  56                         while (status & SR_RBS) {
  57                                 sja1000_rx(dev);
  58                                 status = priv->read_reg(priv, REG_SR);
  59 +                               /* check for absent controller */
  60 +                               if (status == 0xFF && sja1000_is_absent(priv))
  61 +                                       return IRQ_NONE;
  62                         }
  63                 }
  64                 if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
  65 --
  66 1.7.7.4
  67