From: Tim Sell <Timothy.Sell@xxxxxxxxxx>
Whenever the absolute x,y resolution of the video (and mouse) changes, the
back-end sends an inputaction_set_max_xy message indicating the new
resolution. This commit adds the infrastructure to detect and correctly
respond to that message.
There were several reasons this wasn't as easy as it sounds:
* input_set_abs_params() is only effective if it is called prior to
input_register_device(). So we need to free the input_dev and
re-create it whenever the resolution changes.
* Because freeing the input_dev and re-creating it will take us thru
visorinput_close() and visorinput_open() if someone in user-land has the
device open, and because those will end up calling
visorbus_enable_channel_interrupts() and
visorbus_disable_channel_interrupts(), we canNOT just free the input_dev
and re-create it inline within visorinput_channel_interrupt(). We need
to use a workqueue to do it asynchronously.
Signed-off-by: Tim Sell <Timothy.Sell@xxxxxxxxxx>
Signed-off-by: Benjamin Romer <benjamin.romer@xxxxxxxxxx>
---
v2: the patch was resubmitted.
---
drivers/staging/unisys/visorinput/visorinput.c | 71 ++++++++++++++++++++++++++
1 file changed, 71 insertions(+)
diff --git a/drivers/staging/unisys/visorinput/visorinput.c b/drivers/staging/unisys/visorinput/visorinput.c
index 8c22e0f..77e0252 100644
--- a/drivers/staging/unisys/visorinput/visorinput.c
+++ b/drivers/staging/unisys/visorinput/visorinput.c
@@ -28,6 +28,7 @@
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/uuid.h>
+#include <linux/workqueue.h>
#include "version.h"
#include "visorbus.h"
@@ -86,6 +87,11 @@ enum visorinput_device_type {
visorinput_mouse,
};
+struct change_resolution_work {
+ struct work_struct work;
+ unsigned xres, yres;
+};
+
/*
* This is the private data that we store for each device.
* A pointer to this struct is maintained via
@@ -97,6 +103,8 @@ struct visorinput_devdata {
struct rw_semaphore lock_visor_dev; /* lock for dev */
struct input_dev *visorinput_dev;
bool paused;
+ struct workqueue_struct *wq;
+ struct change_resolution_work change_resolution_work_data;
unsigned int keycode_table_bytes; /* size of following array */
/* for keyboard devices: visorkbd_keycode[] + visorkbd_ext_keycode[] */
unsigned char keycode_table[0];
@@ -384,6 +392,10 @@ static void devdata_release(struct kref *kref)
struct visorinput_devdata *devdata =
container_of(kref, struct visorinput_devdata, kref);
unregister_client_input(devdata->visorinput_dev);
+ if (devdata->wq) {
+ flush_workqueue(devdata->wq);
+ destroy_workqueue(devdata->wq);
+ }
kfree(devdata);
}
@@ -401,6 +413,51 @@ static void devdata_put(struct visorinput_devdata *devdata)
kref_put(&devdata->kref, devdata_release);
}
+static void async_change_resolution(struct work_struct *work)
+{
+ struct change_resolution_work *p_change_resolution_work =
+ container_of(work, struct change_resolution_work, work);
+ struct visorinput_devdata *devdata =
+ container_of(p_change_resolution_work,
+ struct visorinput_devdata,
+ change_resolution_work_data);
+
+ down_write(&devdata->lock_visor_dev);
+
+ if (devdata->paused) /* don't touch device/channel when paused */
+ goto out_locked;
+ if (!devdata->visorinput_dev)
+ goto out_locked;
+
+ unregister_client_input(devdata->visorinput_dev);
+ /*
+ * input_set_abs_params is only effective prior to
+ * input_register_device().
+ */
+ devdata->visorinput_dev =
+ register_client_mouse(devdata,
+ p_change_resolution_work->xres,
+ p_change_resolution_work->yres);
+ if (!devdata->visorinput_dev)
+ dev_err(&devdata->dev->device,
+ "failed create of new mouse input dev for new resolution %u,%u\n",
+ p_change_resolution_work->xres,
+ p_change_resolution_work->yres);
+
+out_locked:
+ up_write(&devdata->lock_visor_dev);
+ devdata_put(devdata); /* from schedule_mouse_resolution_change() */
+}
+
+static void schedule_mouse_resolution_change(struct visorinput_devdata *devdata,
+ unsigned xres, unsigned yres)
+{
+ devdata->change_resolution_work_data.xres = xres;
+ devdata->change_resolution_work_data.yres = yres;
+ devdata_get(devdata); /* don't go away until work processed */
+ queue_work(devdata->wq, &devdata->change_resolution_work_data.work);
+}
+
static struct visorinput_devdata *
devdata_create(struct visor_device *dev, enum visorinput_device_type devtype)
{
@@ -415,6 +472,9 @@ devdata_create(struct visor_device *dev, enum visorinput_device_type devtype)
if (!devdata)
return NULL;
devdata->dev = dev;
+ devdata->wq = alloc_ordered_workqueue("visorinput", 0);
+ INIT_WORK(&devdata->change_resolution_work_data.work,
+ async_change_resolution);
init_rwsem(&devdata->lock_visor_dev);
down_write(&devdata->lock_visor_dev);
@@ -678,6 +738,17 @@ visorinput_channel_interrupt(struct visor_device *dev)
input_report_rel(visorinput_dev, REL_WHEEL, -1);
input_sync(visorinput_dev);
break;
+ case inputaction_set_max_xy:
+ /*
+ * we can NOT handle this inline, because this may go
+ * thru a close() path, which will attempt to stop the
+ * worker thread we are running on, which will end up
+ * deadlocking
+ */
+ schedule_mouse_resolution_change(devdata,
+ r.activity.arg1,
+ r.activity.arg2);
+ break;
}
}
out_locked:
--
2.5.0
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