On Mon, May 09, 2011 at 11:38:19PM +0200, Linus Walleij wrote: > From: Virupax Sadashivpetimath <[email protected]> > > It is seen that i2c-nomadik controller randomly stops generating the > interrupts leading to a i2c timeout. As a workaround to this problem, > add retries to the on going transfer on failure. > > Signed-off-by: Virupax Sadashivpetimath > <[email protected]> > Reviewed-by: Jonas ABERG <[email protected]> > Signed-off-by: Linus Walleij <[email protected]> > --- > drivers/i2c/busses/i2c-nomadik.c | 97 > +++++++++++++++++++------------------- > 1 files changed, 49 insertions(+), 48 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-nomadik.c > b/drivers/i2c/busses/i2c-nomadik.c > index f3a0af0..bf061e1 100644 > --- a/drivers/i2c/busses/i2c-nomadik.c > +++ b/drivers/i2c/busses/i2c-nomadik.c > @@ -255,8 +255,6 @@ static int init_hw(struct nmk_i2c_dev *dev) > { > int stat; > > - clk_enable(dev->clk); > - > stat = flush_i2c_fifo(dev); > if (stat) > goto exit; > @@ -271,8 +269,6 @@ static int init_hw(struct nmk_i2c_dev *dev) > dev->cli.operation = I2C_NO_OPERATION; > > exit: > - /* TODO: Why disable clocks after init hw? */ > - clk_disable(dev->clk); > /* > * TODO: What is this delay for? > * Must be pretty pointless since the hw block > @@ -572,6 +568,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, > u32 cause; > struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap); > u32 i2c_sr; > + int j; > > dev->busy = true; > > @@ -579,63 +576,67 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, > regulator_enable(dev->regulator); > pm_runtime_get_sync(&dev->pdev->dev); > > + clk_enable(dev->clk); > + > status = init_hw(dev); > if (status) > - goto out2; > + goto out; > > - clk_enable(dev->clk); > - > - /* setup the i2c controller */ > - setup_i2c_controller(dev); > + for (j = 0; j < 3; j++) { > + /* setup the i2c controller */ > + setup_i2c_controller(dev); > > - for (i = 0; i < num_msgs; i++) { > - if (unlikely(msgs[i].flags & I2C_M_TEN)) { > - dev_err(&dev->pdev->dev, "10 bit addressing" > - "not supported\n"); > + for (i = 0; i < num_msgs; i++) { > + if (unlikely(msgs[i].flags & I2C_M_TEN)) { > + dev_err(&dev->pdev->dev, "10 bit addressing" > + "not supported\n"); > > - status = -EINVAL; > - goto out; > - } > - dev->cli.slave_adr = msgs[i].addr; > - dev->cli.buffer = msgs[i].buf; > - dev->cli.count = msgs[i].len; > - dev->stop = (i < (num_msgs - 1)) ? 0 : 1; > - dev->result = 0; > - > - if (msgs[i].flags & I2C_M_RD) { > - /* it is a read operation */ > - dev->cli.operation = I2C_READ; > - status = read_i2c(dev); > - } else { > - /* write operation */ > - dev->cli.operation = I2C_WRITE; > - status = write_i2c(dev); > - } > - if (status || (dev->result)) { > - i2c_sr = readl(dev->virtbase + I2C_SR); > - /* > - * Check if the controller I2C operation status is set > - * to ABORT(11b). > - */ > - if (((i2c_sr >> 2) & 0x3) == 0x3) { > - /* get the abort cause */ > - cause = (i2c_sr >> 4) > - & 0x7; > - dev_err(&dev->pdev->dev, "%s\n", cause >= > - ARRAY_SIZE(abort_causes) ? > + status = -EINVAL; > + goto out; > + } > + dev->cli.slave_adr = msgs[i].addr; > + dev->cli.buffer = msgs[i].buf; > + dev->cli.count = msgs[i].len; > + dev->stop = (i < (num_msgs - 1)) ? 0 : 1; > + dev->result = 0; > + > + if (msgs[i].flags & I2C_M_RD) { > + /* it is a read operation */ > + dev->cli.operation = I2C_READ; > + status = read_i2c(dev); > + } else { > + /* write operation */ > + dev->cli.operation = I2C_WRITE; > + status = write_i2c(dev); > + } > + if (status || (dev->result)) { > + i2c_sr = readl(dev->virtbase + I2C_SR); > + /* > + * Check if the controller I2C operation status > + * is set to ABORT(11b). > + */ > + if (((i2c_sr >> 2) & 0x3) == 0x3) { > + /* get the abort cause */ > + cause = (i2c_sr >> 4) > + & 0x7; > + dev_err(&dev->pdev->dev, "%s\n", cause > + >= ARRAY_SIZE(abort_causes) ? > "unknown reason" : > abort_causes[cause]); > - } > + } > > - status = status ? status : dev->result; > - goto out; > + status = status ? status : dev->result; > + > + break; > + } > + udelay(I2C_DELAY); > } > - udelay(I2C_DELAY); > + if (status == 0) > + break;
this code is getting a bit complicated, could some of it be factored into a new sub-function? -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
