udlfb: make a local copy of fb_ops

The defio subsystem overwrites the method fb_osp->mmap. That method is
stored in module's static data - and that means that if we have multiple
diplaylink adapters, they will over write each other's method.

In order to avoid interference between multiple adapters, we copy the
fb_ops structure to a device-local memory.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
index fa63a2e359d6..770c1c8cfbd0 100644
--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -1665,7 +1665,8 @@ static void dlfb_init_framebuffer_work(struct work_struct *work)
         dlfb->info = info;
         info->par = dlfb;
         info->pseudo_palette = dlfb->pseudo_palette;
-        info->fbops = &dlfb_ops;
+        dlfb->ops = dlfb_ops;
+        info->fbops = &dlfb->ops;
 
         retval = fb_alloc_cmap(&info->cmap, 256, 0);
         if (retval < 0) {
diff --git a/include/video/udlfb.h b/include/video/udlfb.h
index bc2e9cf34aa5..b4f43d3ac1af 100644
--- a/include/video/udlfb.h
+++ b/include/video/udlfb.h
@@ -51,6 +51,7 @@ struct dlfb_data {
         int base8;
         u32 pseudo_palette[256];
         int blank_mode; /*one of FB_BLANK_ */
+        struct fb_ops ops;
         /* blit-only rendering path metrics, exposed through sysfs */
         atomic_t bytes_rendered; /* raw pixel-bytes driver asked to render */
         atomic_t bytes_identical; /* saved effort with backbuffer comparison */