From 27d0fe189437803d5ad146d508ec2fd77252c73f Mon Sep 17 00:00:00 2001
From: Roland Stoll <roland@xindex.de>
Date: Mon, 11 Feb 2008 13:00:34 -0300
Subject: [PATCH] V4L/DVB (7194): cx88-mpeg: Allow concurrent access to
cx88-mpeg devices
It currently isn't possible to open the frontend device of cx88-mpeg devices
(DVB or Blackbird) multiple times concurrently. (for instance, to attach a
signal monitoring tool while reading a stream, or to send a frequency change
ioctl) This patch fixes that condition.
Signed-off-by: Roland Stoll <roland@xindex.de>
Signed-off-by: Ricardo Cerqueira <v4l@cerqueira.org>
Reviewed-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
---
drivers/media/video/cx88/cx88-mpeg.c | 16 ++++++++++++----
drivers/media/video/cx88/cx88.h | 1 +
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/media/video/cx88/cx88-mpeg.c b/drivers/media/video/cx88/cx88-mpeg.c
index 0aedbeaf94cd7..f12733d6bf728 100644
--- a/drivers/media/video/cx88/cx88-mpeg.c
+++ b/drivers/media/video/cx88/cx88-mpeg.c
@@ -609,13 +609,19 @@ static int cx8802_request_acquire(struct cx8802_driver *drv)
struct cx88_core *core = drv->core;
/* Fail a request for hardware if the device is busy. */
- if (core->active_type_id != CX88_BOARD_NONE)
+ if (core->active_type_id != CX88_BOARD_NONE &&
+ core->active_type_id != drv->type_id)
return -EBUSY;
if (drv->advise_acquire)
{
- core->active_type_id = drv->type_id;
- drv->advise_acquire(drv);
+ core->active_ref++;
+ mutex_lock(&drv->core->lock);
+ if (core->active_type_id == CX88_BOARD_NONE) {
+ core->active_type_id = drv->type_id;
+ drv->advise_acquire(drv);
+ }
+ mutex_unlock(&drv->core->lock);
mpeg_dbg(1,"%s() Post acquire GPIO=%x\n", __FUNCTION__, cx_read(MO_GP0_IO));
}
@@ -628,10 +634,12 @@ static int cx8802_request_release(struct cx8802_driver *drv)
{
struct cx88_core *core = drv->core;
- if (drv->advise_release)
+ if (drv->advise_release && --core->active_ref == 0)
{
+ mutex_lock(&drv->core->lock);
drv->advise_release(drv);
core->active_type_id = CX88_BOARD_NONE;
+ mutex_unlock(&drv->core->lock);
mpeg_dbg(1,"%s() Post release GPIO=%x\n", __FUNCTION__, cx_read(MO_GP0_IO));
}
diff --git a/drivers/media/video/cx88/cx88.h b/drivers/media/video/cx88/cx88.h
index 4e823f2a539a3..37e6d2e4002f5 100644
--- a/drivers/media/video/cx88/cx88.h
+++ b/drivers/media/video/cx88/cx88.h
@@ -336,6 +336,7 @@ struct cx88_core {
/* cx88-video needs to access cx8802 for hybrid tuner pll access. */
struct cx8802_dev *dvbdev;
enum cx88_board_type active_type_id;
+ int active_ref;
};
struct cx8800_dev;
--
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