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| author | Paul Walmsley <paul@pwsan.com> | 2008-11-21 13:39:47 -0800 |
|---|---|---|
| committer | Tony Lindgren <tony@atomide.com> | 2008-11-21 13:39:47 -0800 |
| commit | 3831f154418e058616129942e8175dc4c7e4a1d8 (patch) | |
| tree | 39373d541573f986cce29acd8b54f7e4584e11af /drivers/i2c/busses/i2c-omap.c | |
| parent | c1a473bde4c06e8e6996ce3a33121b7a9a86b4b9 (diff) | |
| download | kernel_samsung_smdk4412-3831f154418e058616129942e8175dc4c7e4a1d8.zip kernel_samsung_smdk4412-3831f154418e058616129942e8175dc4c7e4a1d8.tar.gz kernel_samsung_smdk4412-3831f154418e058616129942e8175dc4c7e4a1d8.tar.bz2 | |
i2c-omap: fix I2C timeouts due to recursive omap_i2c_{un,}idle()
omap_i2c_unidle() and omap_i2c_idle() are called recursively during
omap_i2c_probe(). This is evidently unexpected and will wipe
out the I2C interrupt enable register the second time that
omap_i2c_idle() is called consecutively. Any I2C transactions
following a probe of a bus with at least one device on it will then
time out.
Fix by moving omap_i2c_idle() further up in omap_i2c_probe(). Ensure
the I2C controller is marked as idle before the probe starts. Also
attempt to catch future reappearances of this bug early in development
by warning in omap_i2c_{un,}idle() when they are called recursively.
Problem reported by David Brownell <david-b@pacbell.net>.
Tested on 3430SDP and 2430SDP.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Richard Woodruff <r-woodruff2@ti.com>
Acked-by; Steve Sakoman <steve@sakoman.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'drivers/i2c/busses/i2c-omap.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-omap.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 4aeebad..40a1e4b 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -191,6 +191,8 @@ static void omap_i2c_put_clocks(struct omap_i2c_dev *dev) static void omap_i2c_unidle(struct omap_i2c_dev *dev) { + WARN_ON(!dev->idle); + if (dev->iclk != NULL) clk_enable(dev->iclk); clk_enable(dev->fclk); @@ -203,6 +205,8 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev) { u16 iv; + WARN_ON(dev->idle); + dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0); if (dev->rev1) { @@ -740,6 +744,7 @@ omap_i2c_probe(struct platform_device *pdev) speed = 100; /* Defualt speed */ dev->speed = speed; + dev->idle = 1; dev->dev = &pdev->dev; dev->irq = irq->start; dev->base = ioremap(mem->start, mem->end - mem->start + 1); @@ -788,6 +793,8 @@ omap_i2c_probe(struct platform_device *pdev) dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", pdev->id, r >> 4, r & 0xf, dev->speed); + omap_i2c_idle(dev); + adap = &dev->adapter; i2c_set_adapdata(adap, dev); adap->owner = THIS_MODULE; @@ -804,8 +811,6 @@ omap_i2c_probe(struct platform_device *pdev) goto err_free_irq; } - omap_i2c_idle(dev); - return 0; err_free_irq: |