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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-01 18:24:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-01 18:24:52 -0800 |
| commit | a223c522805d4e9de4903fdd9c14588e558b2c16 (patch) | |
| tree | 5a9f2509feb5a2993be9c93150b5e5d9ebeb3328 | |
| parent | cfa5555cabbc89e31b5866d0473beddc147bae9b (diff) | |
| parent | 844990daa2e69a4258049ba9c2bae1180657dac3 (diff) | |
| download | linux-3.10-a223c522805d4e9de4903fdd9c14588e558b2c16.tar.gz linux-3.10-a223c522805d4e9de4903fdd9c14588e558b2c16.tar.bz2 linux-3.10-a223c522805d4e9de4903fdd9c14588e558b2c16.zip | |
Merge branch 'i2c-embedded/for-3.3' of git://git.pengutronix.de/git/wsa/linux-2.6
i2c bugfix from Wolfram Sang:
"This patch fixes a wrong assumption in the mxs-i2c-driver about a
command queue being done. Without it, we have seen races when the
bus was under load."
* 'i2c-embedded/for-3.3' of git://git.pengutronix.de/git/wsa/linux-2.6:
i2c: mxs: only flag completion when queue is completely done
| -rw-r--r-- | drivers/i2c/busses/i2c-mxs.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 7e78f7c8785..3d471d56bf1 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -72,6 +72,7 @@ #define MXS_I2C_QUEUESTAT (0x70) #define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY 0x00002000 +#define MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK 0x0000001F #define MXS_I2C_QUEUECMD (0x80) @@ -219,14 +220,14 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int ret; int flags; - init_completion(&i2c->cmd_complete); - dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", msg->addr, msg->len, msg->flags, stop); if (msg->len == 0) return -EINVAL; + init_completion(&i2c->cmd_complete); + flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0; if (msg->flags & I2C_M_RD) @@ -286,6 +287,7 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) { struct mxs_i2c_dev *i2c = dev_id; u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK; + bool is_last_cmd; if (!stat) return IRQ_NONE; @@ -300,9 +302,14 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) else i2c->cmd_err = 0; - complete(&i2c->cmd_complete); + is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) & + MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0; + + if (is_last_cmd || i2c->cmd_err) + complete(&i2c->cmd_complete); writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR); + return IRQ_HANDLED; } |