[PATCH] xen,input: try to read screen resolution for xen-kbdfront

Instead of using the default resolution of 800*600 for the pointing
device of xen-kbdfront try to read the resolution of the (virtual)
framebuffer device. Use the default as fallback only.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 drivers/input/misc/xen-kbdfront.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 3900875..0032c81 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/module.h>
+#include <linux/fb.h>
 #include <linux/input.h>
 #include <linux/slab.h>
 

@@ -108,10 +109,11 @@ static irqreturn_t input_handler(int rq, void *dev_id)
 static int xenkbd_probe(struct xenbus_device *dev,
 				  const struct xenbus_device_id *id)
 {
-	int ret, i;
+	int ret, i, width, height;
 	unsigned int abs;
 	struct xenkbd_info *info;
 	struct input_dev *kbd, *ptr;
+	struct fb_info *fb0;
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {

@@ -173,9 +175,16 @@ static int xenkbd_probe(struct xenbus_device *dev,
 	ptr->id.product = 0xfffe;
 
 	if (abs) {
+		width = XENFB_WIDTH;
+		height = XENFB_HEIGHT;
+		fb0 = registered_fb[0];
+		if (fb0) {
+			width = fb0->var.xres_virtual;
+			height = fb0->var.yres_virtual;
+		}
 		__set_bit(EV_ABS, ptr->evbit);
-		input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
-		input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
+		input_set_abs_params(ptr, ABS_X, 0, width, 0, 0);
+		input_set_abs_params(ptr, ABS_Y, 0, height, 0, 0);
 	} else {
 		input_set_capability(ptr, EV_REL, REL_X);
 		input_set_capability(ptr, EV_REL, REL_Y);

-- 
2.10.2

On Tue, Jan 24, 2017 at 01:09:55PM +0100, Juergen Gross wrote:

This will break if !CONFIG_FBi I think. While i see that xen.config has
it on I wonder if it is still possible to turn it off (either randconfig
or intentionally).

Thanks.

-- 
Dmitry

Hi Juergen,

[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on v4.10-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Juergen-Gross/xen-input-try-to-read-screen-resolution-for-xen-kbdfront/20170125-010022
base:   https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
config: x86_64-randconfig-h0-01250255 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   drivers/built-in.o: In function `xenkbd_probe':

quoted

xen-kbdfront.c:(.text+0x3dc506): undefined reference to `registered_fb'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

On 24/01/17 19:47, Dmitry Torokhov wrote:

On Tue, Jan 24, 2017 at 01:09:55PM +0100, Juergen Gross wrote:

quoted

Instead of using the default resolution of 800*600 for the pointing
device of xen-kbdfront try to read the resolution of the (virtual)
framebuffer device. Use the default as fallback only.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 drivers/input/misc/xen-kbdfront.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index 3900875..0032c81 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/module.h>
+#include <linux/fb.h>
 #include <linux/input.h>
 #include <linux/slab.h>
 

@@ -108,10 +109,11 @@ static irqreturn_t input_handler(int rq, void *dev_id)
 static int xenkbd_probe(struct xenbus_device *dev,
 				  const struct xenbus_device_id *id)
 {
-	int ret, i;
+	int ret, i, width, height;
 	unsigned int abs;
 	struct xenkbd_info *info;
 	struct input_dev *kbd, *ptr;
+	struct fb_info *fb0;
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {

@@ -173,9 +175,16 @@ static int xenkbd_probe(struct xenbus_device *dev,
 	ptr->id.product = 0xfffe;
 
 	if (abs) {
+		width = XENFB_WIDTH;
+		height = XENFB_HEIGHT;
+		fb0 = registered_fb[0];

This will break if !CONFIG_FBi I think. While i see that xen.config has
it on I wonder if it is still possible to turn it off (either randconfig
or intentionally).

kbuild robot says it is. :-(

Sending V2.


Thanks,

Juergen