Attachment 578165 Details for Bug 812895 – Fix DVB frontend regression when switching back to DVB-S

[patch] Fix DVB frontend regression when switching back to DVB-S

dvb_frontend_switch_regression_fix.patch (text/plain), 2.34 KB, created by Mauro Carvalho Chehab on 2012-04-17 21:44:17 UTC

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Creator: Mauro Carvalho Chehab

Created: 2012-04-17 21:44:17 UTC

Size: 2.34 KB

patch

obsolete

>From c6c6fa8dcc27aad6ce3467544be0f57fd82b99a3 Mon Sep 17 00:00:00 2001
>From: Mauro Carvalho Chehab <mchehab@redhat.com>
>Date: Tue, 17 Apr 2012 18:32:19 -0300
>Subject: [PATCH] [media] dvb_frontend: Fix a regression when switching back
> to DVB-S
>
>There are some softwares (Kaffeine and likely xine) that uses a
>DVBv5 call to switch to DVB-S2, but expects that a DVBv3 call to
>switch back to DVB-S. Well, this is not right, as a DVBv3 call
>doesn't know anything about delivery systems.
>
>However, as, by accident, this used to work, we need to restore its
>behavior, in order to avoid regressions with those softwares.
>
>Reported on this Fedora 16 bugzilla:
>	https://bugzilla.redhat.com/show_bug.cgi?id=812895
>
>Reported-by: Dieter Roever <Dieter.Roever@gmx.de>
>Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
>
>diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
>index 4555baa..bb582fd 100644
>--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
>+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
>@@ -1443,6 +1443,28 @@ static int set_delivery_system(struct dvb_frontend *fe, u32 desired_system)
> 				__func__);
> 			return -EINVAL;
> 		}
>+		/*
>+		 * Get a delivery system that is compatible with DVBv3
>+		 * NOTE: in order for this to work with softwares like Kaffeine that
>+		 *	uses a DVBv5 call for DVB-S2 and a DVBv3 call to go back to
>+		 *	DVB-S, drivers that support both should put the SYS_DVBS entry
>+		 *	before the SYS_DVBS2, otherwise it won't switch back to DVB-S.
>+		 *	The real fix is that userspace applications should not use DVBv3
>+		 *	and not trust on calling FE_SET_FRONTEND to switch the delivery
>+		 *	system.
>+		 */
>+		ncaps = 0;
>+		while (fe->ops.delsys[ncaps] && ncaps < MAX_DELSYS) {
>+			if (fe->ops.delsys[ncaps] == desired_system) {
>+				delsys = desired_system;
>+				break;
>+			}
>+			ncaps++;
>+		}
>+		if (delsys == SYS_UNDEFINED) {
>+			dprintk("%s() Couldn't find a delivery system that matches %d\n",
>+				__func__, desired_system);
>+		}
> 	} else {
> 		/*
> 		 * This is a DVBv5 call. So, it likely knows the supported
>@@ -1491,9 +1513,10 @@ static int set_delivery_system(struct dvb_frontend *fe, u32 desired_system)
> 				__func__);
> 			return -EINVAL;
> 		}
>-		c->delivery_system = delsys;
> 	}
> 
>+	c->delivery_system = delsys;
>+
> 	/*
> 	 * The DVBv3 or DVBv5 call is requesting a different system. So,
> 	 * emulation is needed.

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Attachments on bug 812895: 578165