From 6757ccc57d2cc4ab4e63d8aee97f2e6b9f998990 Mon Sep 17 00:00:00 2001 From: Peter Beutner Date: Thu, 7 Jul 2005 17:57:36 -0700 Subject: [PATCH] [PATCH] dvb: core: fix race condition in FE_READ_STATUS ioctl Fix a race condition where an application which issued a FE_READ_STATUS ioctl directly after FE_SET_FRONTEND would see an old status, i.e. FE_READ_STATUS would be executed before the frontend thread has even seen the tungin request from FE_SET_FRONTEND. Signed-off-by: Peter Beutner Signed-off-by: Johannes Stezenbach Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/media/dvb/dvb-core/dvb_frontend.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c index f11daae91cd4..e561ac1e1b16 100644 --- a/drivers/media/dvb/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb/dvb-core/dvb_frontend.c @@ -626,11 +626,21 @@ static int dvb_frontend_ioctl(struct inode *inode, struct file *file, break; } - case FE_READ_STATUS: + case FE_READ_STATUS: { + fe_status_t* status = parg; + + /* if retune was requested but hasn't occured yet, prevent + * that user get signal state from previous tuning */ + if(fepriv->state == FESTATE_RETUNE) { + err=0; + *status = 0; + break; + } + if (fe->ops->read_status) - err = fe->ops->read_status(fe, (fe_status_t*) parg); + err = fe->ops->read_status(fe, status); break; - + } case FE_READ_BER: if (fe->ops->read_ber) err = fe->ops->read_ber(fe, (__u32*) parg); -- 2.20.1