From 6ae23224557d797439d02f6ce5d10a82ab544b21 Mon Sep 17 00:00:00 2001 From: Juergen Lock Date: Sun, 23 Dec 2012 17:23:06 -0300 Subject: [PATCH] [media] dvb_frontend: fix ioctls failing if frontend open/closed too fast That likely fixes this MythTV ticket: http://code.mythtv.org/trac/ticket/10830 (which btw affects all usb tuners I tested as well, pctv452e, dib0700, af9015) pctv452e is still possibly broken with MythTV even after this fix; it does work with VDR here tho despite I2C errors. Reduced testcase: http://people.freebsd.org/~nox/tmp/ioctltst.c Thanx to devinheitmueller and crope from #linuxtv for helping with this fix! :) Signed-off-by: Juergen Lock Signed-off-by: Michael Krufky Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-core/dvb_frontend.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index 49d95040096a..9b4a47c104a1 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -603,6 +603,7 @@ static int dvb_frontend_thread(void *data) enum dvbfe_algo algo; bool re_tune = false; + bool semheld = false; dev_dbg(fe->dvb->device, "%s:\n", __func__); @@ -626,6 +627,8 @@ restart: if (kthread_should_stop() || dvb_frontend_is_exiting(fe)) { /* got signal or quitting */ + if (!down_interruptible(&fepriv->sem)) + semheld = true; fepriv->exit = DVB_FE_NORMAL_EXIT; break; } @@ -741,6 +744,8 @@ restart: fepriv->exit = DVB_FE_NO_EXIT; mb(); + if (semheld) + up(&fepriv->sem); dvb_frontend_wakeup(fe); return 0; } @@ -1823,16 +1828,20 @@ static int dvb_frontend_ioctl(struct file *file, int err = -ENOTTY; dev_dbg(fe->dvb->device, "%s: (%d)\n", __func__, _IOC_NR(cmd)); - if (fepriv->exit != DVB_FE_NO_EXIT) + if (down_interruptible(&fepriv->sem)) + return -ERESTARTSYS; + + if (fepriv->exit != DVB_FE_NO_EXIT) { + up(&fepriv->sem); return -ENODEV; + } if ((file->f_flags & O_ACCMODE) == O_RDONLY && (_IOC_DIR(cmd) != _IOC_READ || cmd == FE_GET_EVENT || - cmd == FE_DISEQC_RECV_SLAVE_REPLY)) + cmd == FE_DISEQC_RECV_SLAVE_REPLY)) { + up(&fepriv->sem); return -EPERM; - - if (down_interruptible (&fepriv->sem)) - return -ERESTARTSYS; + } if ((cmd == FE_SET_PROPERTY) || (cmd == FE_GET_PROPERTY)) err = dvb_frontend_ioctl_properties(file, cmd, parg);