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| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2014-04-15 21:30:00 +0400 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2014-04-25 00:22:53 +0400 |
| commit | a9edcdedbd3d8f3ffcd7bdcab5812707a25e554e (patch) | |
| tree | 5eff58f9133f3e21f8b2134867cefc1c2ec4b817 | |
| parent | 78c181bc8a75d3f0624eaf24aa8265d441990c8c (diff) | |
| download | linux-a9edcdedbd3d8f3ffcd7bdcab5812707a25e554e.tar.xz | |
can: sja1000_isa: add locking for indirect register access mode
When accessing the SJA1000 controller registers in the indirect access mode,
writing the register number and reading/writing the data has to be an atomic
attempt.
As the sja1000_isa driver is an old style driver with a fixed number of
instances the locking variable depends on the same index like all the other
configuration elements given on the module command line.
As a positive side effect dev->dev_id is populated by the instance index,
which was missing in 3e66d0138c05d9 ("can: populate netdev::dev_id for udev
discrimination").
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | drivers/net/can/sja1000/sja1000_isa.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/net/can/sja1000/sja1000_isa.c b/drivers/net/can/sja1000/sja1000_isa.c index df136a2516c4..014695d7e6a3 100644 --- a/drivers/net/can/sja1000/sja1000_isa.c +++ b/drivers/net/can/sja1000/sja1000_isa.c @@ -46,6 +46,7 @@ static int clk[MAXDEV]; static unsigned char cdr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff}; static unsigned char ocr[MAXDEV] = {[0 ... (MAXDEV - 1)] = 0xff}; static int indirect[MAXDEV] = {[0 ... (MAXDEV - 1)] = -1}; +static spinlock_t indirect_lock[MAXDEV]; /* lock for indirect access mode */ module_param_array(port, ulong, NULL, S_IRUGO); MODULE_PARM_DESC(port, "I/O port number"); @@ -101,19 +102,26 @@ static void sja1000_isa_port_write_reg(const struct sja1000_priv *priv, static u8 sja1000_isa_port_read_reg_indirect(const struct sja1000_priv *priv, int reg) { - unsigned long base = (unsigned long)priv->reg_base; + unsigned long flags, base = (unsigned long)priv->reg_base; + u8 readval; + spin_lock_irqsave(&indirect_lock[priv->dev->dev_id], flags); outb(reg, base); - return inb(base + 1); + readval = inb(base + 1); + spin_unlock_irqrestore(&indirect_lock[priv->dev->dev_id], flags); + + return readval; } static void sja1000_isa_port_write_reg_indirect(const struct sja1000_priv *priv, int reg, u8 val) { - unsigned long base = (unsigned long)priv->reg_base; + unsigned long flags, base = (unsigned long)priv->reg_base; + spin_lock_irqsave(&indirect_lock[priv->dev->dev_id], flags); outb(reg, base); outb(val, base + 1); + spin_unlock_irqrestore(&indirect_lock[priv->dev->dev_id], flags); } static int sja1000_isa_probe(struct platform_device *pdev) @@ -169,6 +177,7 @@ static int sja1000_isa_probe(struct platform_device *pdev) if (iosize == SJA1000_IOSIZE_INDIRECT) { priv->read_reg = sja1000_isa_port_read_reg_indirect; priv->write_reg = sja1000_isa_port_write_reg_indirect; + spin_lock_init(&indirect_lock[idx]); } else { priv->read_reg = sja1000_isa_port_read_reg; priv->write_reg = sja1000_isa_port_write_reg; @@ -198,6 +207,7 @@ static int sja1000_isa_probe(struct platform_device *pdev) platform_set_drvdata(pdev, dev); SET_NETDEV_DEV(dev, &pdev->dev); + dev->dev_id = idx; err = register_sja1000dev(dev); if (err) { |