From: Thomas Niederprüm Date: Tue, 31 Mar 2015 18:27:08 +0000 (+0200) Subject: fbdev: ssd1307fb: Allocate page aligned video memory. X-Git-Tag: firefly_0821_release~176^2~1479^2~49 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=facd94bc458af12e1ebab06cfc3b8e7a41906622;p=firefly-linux-kernel-4.4.55.git fbdev: ssd1307fb: Allocate page aligned video memory. Currently the videomemory is allocated by kmalloc, making it a memory region that is not necessarily page aligend. This leads to problems upon mmap call, where the video memory's address gets aligned to the next page boundary. The result is that the userspace program that issued the mmap call is not able to access the video memory from the start to the next page boundary. This patch changes the allocation of the video memory to use __get_free_pages() in order to obtain memory that is aligned to page boundaries. Signed-off-by: Thomas Niederprüm Acked-by: Maxime Ripard Signed-off-by: Tomi Valkeinen --- diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 61e0ce866506..8d34c5651187 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -489,7 +489,8 @@ 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 = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, + get_order(vmem_size)); if (!vmem) { dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); ret = -ENOMEM; @@ -573,6 +574,7 @@ static int ssd1307fb_remove(struct i2c_client *client) if (par->ops->remove) par->ops->remove(par); fb_deferred_io_cleanup(info); + __free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len)); framebuffer_release(info); return 0;