[PATCH 3.16 061/328] udlfb: make a local copy of fb_ops

Ben Hutchings
2018-12-09T22:04:23Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit 2c29cfc3eaf11779176bf41475cfca49bccba11c upstream.

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>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[bwh: Backported to 3.16: Pointer to struct dlfb_data is named "dev" rather
than "dlfb"]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/video/fbdev/udlfb.c | 3 ++-
include/video/udlfb.h | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -1680,7 +1680,8 @@ static void dlfb_init_framebuffer_work(s
dev->info = info;
info->par = dev;
info->pseudo_palette = dev->pseudo_palette;
- info->fbops = &dlfb_ops;
+ dev->ops = dlfb_ops;
+ info->fbops = &dev->ops;

retval = fb_alloc_cmap(&info->cmap, 256, 0);
if (retval < 0) {
--- 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 */