| Message ID | 20231231130555.1415-1-yongsuyoo0215@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | media: dvb_ca_en50221: Add a returing EBUSY logic into CA_RESET | expand |
diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c index baf64540dc00..506a46844ad8 100644 --- a/drivers/media/dvb-core/dvb_ca_en50221.c +++ b/drivers/media/dvb-core/dvb_ca_en50221.c @@ -1362,7 +1362,8 @@ static int dvb_ca_en50221_io_do_ioctl(struct file *file, struct dvb_ca_slot *sl = &ca->slot_info[slot]; mutex_lock(&sl->slot_lock); - if (sl->slot_state != DVB_CA_SLOTSTATE_NONE) { + if ((sl->slot_state == DVB_CA_SLOTSTATE_RUNNING) || + (sl->slot_state == DVB_CA_SLOTSTATE_INVALID)) { dvb_ca_en50221_slot_shutdown(ca, slot); if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE) dvb_ca_en50221_camchange_irq(ca->pub,
From: Yongsu yoo <yongsuyoo0215@gmail.com> Signed-off-by:Yongsu Yoo <yongsuyoo0215@gmail.com> In source/drivers/media/dvb-core/dvb_ca_en50221.c, if the CA_RESET ioctl is called, in a normal case, the state of the thread of the dvb_ca_en50221_thread_state_machine will transit like below order. DVB_CA_SLOTSTATE_NONE -> DVB_CA_SLOTSTATE_UNINITIALISED -> DVB_CA_SLOTSTATE_WAITREADY -> DVB_CA_SLOTSTATE_VALIDATE -> DVB_CA_SLOTSTATE_WAITFR -> DVB_CA_SLOTSTATE_LINKINIT -> DVB_CA_SLOTSTATE_RUNNING But in some problem cases, the state will become DVB_CA_SLOTSTATE_INVALID. Among the above mentioned states, the DVB_CA_SLOTSTATE_NONE and the DVB_CA_SLOTSTATE_INVALID are "already stablized" states, whereas other states are "transiting" states. The "already stablized" states mean no matter how long time we wait, the state will not be changed. The "transiting" states mean the states whose final state is not yet determined. The state keeps to be changed. Only after some time passes, we get to know whether the final state will be DVB_CA_SLOTSTATE_RUNNING or DVB_CA_SLOTSTATE_INVALID. During the "transiting" states, we do not yet know whether the CA_RESET operation, which triggered the "transiting" states, will succeed or fail. For this reason, during the "transiting" states, if another CA_RESET ioctl is called and if this new CA_RESET ioctl operation begins again, it will be meaningless and waste time. For preventing this problem from happening, we make CA_RESET ioctl do nothing and only return EBUSY if the ioctl is called during the "transiting" states. --- drivers/media/dvb-core/dvb_ca_en50221.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)