From 14e3cdbb00a885eedc95c0cf8eda8fe28d26d6b4 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 19 Jun 2019 10:24:17 -0300 Subject: media: don't drop front-end reference count for ->detach A bugfix introduce a link failure in configurations without CONFIG_MODULES: In file included from drivers/media/usb/dvb-usb/pctv452e.c:20:0: drivers/media/usb/dvb-usb/pctv452e.c: In function 'pctv452e_frontend_attach': drivers/media/dvb-frontends/stb0899_drv.h:151:36: error: weak declaration of 'stb0899_attach' being applied to a already existing, static definition The problem is that the !IS_REACHABLE() declaration of stb0899_attach() is a 'static inline' definition that clashes with the weak definition. I further observed that the bugfix was only done for one of the five users of stb0899_attach(), the other four still have the problem. This reverts the bugfix and instead addresses the problem by not dropping the reference count when calling '->detach()', instead we call this function directly in dvb_frontend_put() before dropping the kref on the front-end. I first submitted this in early 2018, and after some discussion it was apparently discarded. While there is a long-term plan in place, that plan is obviously not nearing completion yet, and the current kernel is still broken unless this patch is applied. Link: https://patchwork.kernel.org/patch/10140175/ Link: https://patchwork.linuxtv.org/patch/54831/ Cc: Max Kellermann Cc: Wolfgang Rohdewald Cc: stable@vger.kernel.org Fixes: f686c14364ad ("[media] stb0899: move code to "detach" callback") Fixes: 6cdeaed3b142 ("media: dvb_usb_pctv452e: module refcount changes were unbalanced") Signed-off-by: Arnd Bergmann Signed-off-by: Sean Young Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb/pctv452e.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'drivers/media/usb') diff --git a/drivers/media/usb/dvb-usb/pctv452e.c b/drivers/media/usb/dvb-usb/pctv452e.c index d6b36e4f33d2..441d878fc22c 100644 --- a/drivers/media/usb/dvb-usb/pctv452e.c +++ b/drivers/media/usb/dvb-usb/pctv452e.c @@ -909,14 +909,6 @@ static int pctv452e_frontend_attach(struct dvb_usb_adapter *a) &a->dev->i2c_adap); if (!a->fe_adap[0].fe) return -ENODEV; - - /* - * dvb_frontend will call dvb_detach for both stb0899_detach - * and stb0899_release but we only do dvb_attach(stb0899_attach). - * Increment the module refcount instead. - */ - symbol_get(stb0899_attach); - if ((dvb_attach(lnbp22_attach, a->fe_adap[0].fe, &a->dev->i2c_adap)) == NULL) err("Cannot attach lnbp22\n"); -- cgit v1.2.3-59-g8ed1b