[PATCH RESEND] i2c: mxs: only flag completion when queue is completely done
From: Wolfram Sang <hidden>
Date: 2012-02-16 14:47:44
Also in:
linux-i2c
Subsystem:
i2c subsystem, i2c subsystem host drivers, the rest · Maintainers:
Andi Shyti, Linus Torvalds
The hardware generates an interrupt for every completed command in the queue while the code assumed that it will only generate one interrupt when the queue is empty. So, explicitly check if the queue is really empty. This patch fixed problems which occurred due to high traffic on the bus. While we are here, move the completion-initialization after the parameter error checking. Signed-off-by: Wolfram Sang <redacted> Cc: Shawn Guo <redacted> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Lothar Wa?mann <redacted> Cc: Ben Dooks <redacted> --- Ben, will you send this to Linus? Should get a stable tag, too, IMO. 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 7e78f7c..3d471d5 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; }
--
1.7.8.3