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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>
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@ -609,13 +609,19 @@ static int cx8802_request_acquire(struct cx8802_driver *drv)
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struct cx88_core *core = drv->core;
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/* Fail a request for hardware if the device is busy. */
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if (core->active_type_id != CX88_BOARD_NONE)
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if (core->active_type_id != CX88_BOARD_NONE &&
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core->active_type_id != drv->type_id)
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return -EBUSY;
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if (drv->advise_acquire)
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{
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core->active_type_id = drv->type_id;
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drv->advise_acquire(drv);
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core->active_ref++;
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mutex_lock(&drv->core->lock);
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if (core->active_type_id == CX88_BOARD_NONE) {
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core->active_type_id = drv->type_id;
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drv->advise_acquire(drv);
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}
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mutex_unlock(&drv->core->lock);
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mpeg_dbg(1,"%s() Post acquire GPIO=%x\n", __FUNCTION__, cx_read(MO_GP0_IO));
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}
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@ -628,10 +634,12 @@ static int cx8802_request_release(struct cx8802_driver *drv)
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{
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struct cx88_core *core = drv->core;
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if (drv->advise_release)
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if (drv->advise_release && --core->active_ref == 0)
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{
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mutex_lock(&drv->core->lock);
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drv->advise_release(drv);
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core->active_type_id = CX88_BOARD_NONE;
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mutex_unlock(&drv->core->lock);
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mpeg_dbg(1,"%s() Post release GPIO=%x\n", __FUNCTION__, cx_read(MO_GP0_IO));
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}
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@ -336,6 +336,7 @@ struct cx88_core {
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/* cx88-video needs to access cx8802 for hybrid tuner pll access. */
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struct cx8802_dev *dvbdev;
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enum cx88_board_type active_type_id;
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int active_ref;
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};
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struct cx8800_dev;
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