Am Tue, 3 Mar 2015 09:52:55 +0100
schrieb Maxime Ripard [off-list ref]:

Hi,

On Sun, Mar 01, 2015 at 11:27:55PM +0100, Thomas Niederprüm wrote:

quoted

It makes sense to use vmalloc to allocate the video buffer since it
has to be page aligned memory for using it with mmap. Also deffered
io seems buggy in combination with kmalloc'ed memory (crash on
unloading the module).

Signed-off-by: Thomas Niederprüm <redacted>
---
 drivers/video/fbdev/ssd1307fb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c

b/drivers/video/fbdev/ssd1307fb.c index 61e0ce8..25dd08d 100644

--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c

@@ -11,6 +11,7 @@
 #include <linux/i2c.h>
 #include <linux/fb.h>
 #include <linux/uaccess.h>
+#include <linux/vmalloc.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pwm.h>

@@ -489,7 +490,7 @@ static int ssd1307fb_probe(struct i2c_client

*client, 
 	vmem_size = par->width * par->height / 8;
 
-	vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
+	vmem = vzalloc(vmem_size);
 	if (!vmem) {
 		dev_err(&client->dev, "Couldn't allocate graphical
memory.\n"); ret = -ENOMEM;

@@ -559,6 +560,7 @@ panel_init_error:
 		par->ops->remove(par);
 reset_oled_error:
 	fb_deferred_io_cleanup(info);
+	vfree(vmem);
 fb_alloc_error:
 	framebuffer_release(info);
 	return ret;

Don't you need the vfree in the remove too?

Yes, of course. Memory will be freed in v3

Maxime