On Wed, 29 Aug 2012, Sylwester Nawrocki wrote:

Hi,

On 08/29/2012 12:11 PM, Josh Wu wrote:

quoted

This patch fix the bug: ISI driver's platform data became invalid 
when isi platform data's attribution is __initdata.

If the isi platform data is passed as __initdata. Then we need store
it in driver allocated memory. otherwise when we use it out of the 
probe() function, then the isi platform data is invalid.

Signed-off-by: Josh Wu <redacted>
---
 drivers/media/platform/soc_camera/atmel-isi.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
index ec3f6a0..dc0fdec 100644
--- a/drivers/media/platform/soc_camera/atmel-isi.c
+++ b/drivers/media/platform/soc_camera/atmel-isi.c

@@ -926,6 +926,7 @@ static int __devexit atmel_isi_remove(struct platform_device *pdev)
 	clk_put(isi->mck);
 	clk_unprepare(isi->pclk);
 	clk_put(isi->pclk);
+	kfree(isi->pdata);
 	kfree(isi);
 
 	return 0;

@@ -968,8 +969,15 @@ static int __devinit atmel_isi_probe(struct platform_device *pdev)
 		goto err_alloc_isi;
 	}
 
+	isi->pdata = kzalloc(sizeof(struct isi_platform_data), GFP_KERNEL);
+	if (!isi->pdata) {
+		ret = -ENOMEM;
+		dev_err(&pdev->dev, "Can't allocate isi platform data!\n");
+		goto err_alloc_isi_pdata;
+	}
+	memcpy(isi->pdata, pdata, sizeof(struct isi_platform_data));
+

Why not just embed struct isi_platform_data in struct atmel_isi and drop this
another kzalloc() ?
Then you could simply do isi->pdata = *pdata.

Also, is this going to work when this driver is build and as a module
and its loading is deferred past system booting ? At that time the driver's
platform data may be well discarded.

Right, it will be gone, I think.

You may wan't to duplicate it on the
running boards in board code with kmemdup() or something.

How about removing __initdata from board code?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/