From 59b1842da1c6f33ad2e8da82d3dfb3445751d964 Mon Sep 17 00:00:00 2001 From: Darron Broad Date: Sat, 11 Oct 2008 11:44:05 -0300 Subject: V4L/DVB (9227): MFE: Add multi-frontend mutual exclusion This add frontend R/W mutual exclusion. Prior to this point in time it was possible to open both frontends simultaneously which an MFE card cannot support. In order to stop this, a delayed open is performed which has the following function: - Return EBUSY after a configurable amount of time if a frontend is unavailable due to the other being in use. - Only allow opening of a frontend if the kernel thread of the other has stopped. This solution was chosen to allow switching between frontends to work as seamlessly as possible. When both frontends are actually opened simultaneously then one will only open, but if quick switching is performed between one of many then the new open will succeed in a clean fashion rather than interrupting a kernel thread. Signed-off-by: Darron Broad Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf-dvb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/media/video/videobuf-dvb.c') diff --git a/drivers/media/video/videobuf-dvb.c b/drivers/media/video/videobuf-dvb.c index a0a80e1e79e3..af0b75cda6fd 100644 --- a/drivers/media/video/videobuf-dvb.c +++ b/drivers/media/video/videobuf-dvb.c @@ -140,7 +140,8 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f, struct module *module, void *adapter_priv, struct device *device, - short *adapter_nr) //NEW + short *adapter_nr, + int mfe_shared) { struct list_head *list, *q; struct videobuf_dvb_frontend *fe; @@ -153,7 +154,7 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f, } /* Bring up the adapter */ - res = videobuf_dvb_register_adapter(f, module, adapter_priv, device, fe->dvb.name, adapter_nr); //NEW + res = videobuf_dvb_register_adapter(f, module, adapter_priv, device, fe->dvb.name, adapter_nr, mfe_shared); if (res < 0) { printk(KERN_WARNING "videobuf_dvb_register_adapter failed (errno = %d)\n", res); goto err; @@ -181,7 +182,8 @@ int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe, void *adapter_priv, struct device *device, char *adapter_name, - short *adapter_nr) //NEW + short *adapter_nr, + int mfe_shared) { int result; @@ -194,6 +196,7 @@ int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe, adapter_name, result); } fe->adapter.priv = adapter_priv; + fe->adapter.mfe_shared = mfe_shared; return result; } -- cgit v1.2.3