lirc_zilog bugs

This driver has a few problems, however the driver has been removed from staging in v4.16 (replaced by a new driver). Please can these patches be included in the 4.14.* stable tree.

Sean Young (2):
Revert "media: lirc_zilog: driver only sends LIRCCODE"
media: staging: lirc_zilog: incorrect reference counting

 drivers/staging/media/lirc/lirc_zilog.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

2.14.3

The lirc config documented here
https://www.blushingpenguin.com/mark/blog/?p=24 uses raw_codes for sending IR. Each key only has one pulse, which in fact is an index into the haup-ir-blaster.bin file. Changing the driver to LIRCCODE (although more accurate) breaks this configuration.

This code has been replaced completely in kernel v4.16 by a new driver, see commit acaa34bf06e9 ("media: rc: implement zilog transmitter"), and commit f95367a7b758 ("media: staging: remove lirc_zilog driver").

This reverts commit 89d8a2cc51d1f29ea24a0b44dde13253141190a0.

---
 drivers/staging/media/lirc/lirc_zilog.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

index 71af13bd0ebd..26dd32d5b5b2 100644
@@ -288,7 +288,7 @@ static void release_ir_tx(struct kref *ref)
 	struct IR_tx *tx = container_of(ref, struct IR_tx, ref);
 	struct IR *ir = tx->ir;
 
-	ir->l.features &= ~LIRC_CAN_SEND_LIRCCODE;
+	ir->l.features &= ~LIRC_CAN_SEND_PULSE;
 	/* Don't put_ir_device(tx->ir) here, so our lock doesn't get freed */
 	ir->tx = NULL;
 	kfree(tx);

@@ -1267,14 +1267,14 @@ static long ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 		if (!(features & LIRC_CAN_SEND_MASK))
 			return -ENOTTY;
 
-		result = put_user(LIRC_MODE_LIRCCODE, uptr);
+		result = put_user(LIRC_MODE_PULSE, uptr);
 		break;
 	case LIRC_SET_SEND_MODE:
 		if (!(features & LIRC_CAN_SEND_MASK))
 			return -ENOTTY;
 
 		result = get_user(mode, uptr);
-		if (!result && mode != LIRC_MODE_LIRCCODE)
+		if (!result && mode != LIRC_MODE_PULSE)
 			return -EINVAL;
 		break;
 	default:

@@ -1512,7 +1512,7 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		kref_init(&tx->ref);
 		ir->tx = tx;
 
-		ir->l.features |= LIRC_CAN_SEND_LIRCCODE;
+		ir->l.features |= LIRC_CAN_SEND_PULSE;
 		mutex_init(&tx->client_lock);
 		tx->c = client;
 		tx->need_boot = 1;

2.14.3

Whenever poll is called, the reference count is increased but never decreased. This means that on rmmod, the lirc_thread is not stopped, and will trample over freed memory.

Zilog/Hauppauge IR driver unloaded

BUG: unable to handle kernel paging request at ffffffffc17ba640
Oops: 0010 [#1] SMP
CPU: 1 PID: 667 Comm: zilog-rx-i2c-1 Tainted: P         C OE   4.13.16-302.fc27.x86_64 #1
Hardware name: Gigabyte Technology Co., Ltd. GA-MA790FXT-UD5P/GA-MA790FXT-UD5P, BIOS F6 08/06/2009
task: ffff964eb452ca00 task.stack: ffffb254414dc000
RIP: 0010:0xffffffffc17ba640
RSP: 0018:ffffb254414dfe78 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff964ec1b35890 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246
RBP: ffffb254414dff00 R08: 000000000000036e R09: ffff964ecfc8dfd0
R10: ffffb254414dfe78 R11: 00000000000f4240 R12: ffff964ec2bf28a0
R13: ffff964ec1b358a8 R14: ffff964ec1b358d0 R15: ffff964ec1b35800
FS:  0000000000000000(0000) GS:ffff964ecfc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc17ba640 CR3: 000000023058c000 CR4: 00000000000006e0
Call Trace:
 kthread+0x125/0x140
 ? kthread_park+0x60/0x60
 ? do_syscall_64+0x67/0x140
 ret_from_fork+0x25/0x30
Code:  Bad RIP value.
RIP: 0xffffffffc17ba640 RSP: ffffb254414dfe78

CR2: ffffffffc17ba640

Note that zilog-rx-i2c-1 should have exited by now, but hasn't due to the missing put in poll().

This code has been replaced completely in kernel v4.16 by a new driver, see commit acaa34bf06e9 ("media: rc: implement zilog transmitter"), and commit f95367a7b758 ("media: staging: remove lirc_zilog driver").

---
 drivers/staging/media/lirc/lirc_zilog.c | 1 +
 1 file changed, 1 insertion(+)

index 26dd32d5b5b2..e35e1b2160e3 100644
@@ -1228,6 +1228,7 @@ static unsigned int poll(struct file *filep, poll_table *wait)
 
 	dev_dbg(ir->l.dev, "%s result = %s\n", __func__,
 		ret ? "POLLIN|POLLRDNORM" : "none");
+	put_ir_rx(rx, false);
 	return ret;
 }
 

2.14.3