[git:media_tree/fixes] media: ir_toy: prevent device from hanging during transmit
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Date: 2021-09-19 09:21:23
Subsystem:
media input infrastructure (v4l/dvb), rc-core / lirc framework, the rest · Maintainers:
Mauro Carvalho Chehab, Sean Young, Linus Torvalds
This is an automatic generated email to let you know that the following patch were queued: Subject: media: ir_toy: prevent device from hanging during transmit Author: Sean Young [off-list ref] Date: Tue Sep 14 16:57:46 2021 +0200 If the IR Toy is receiving IR while a transmit is done, it may end up hanging. We can prevent this from happening by re-entering sample mode just before issuing the transmit command. Link: https://github.com/bengtmartensson/HarcHardware/discussions/25 Cc: stable@vger.kernel.org Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> drivers/media/rc/ir_toy.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) ---
diff --git a/drivers/media/rc/ir_toy.c b/drivers/media/rc/ir_toy.c
index 3e729a17b35f..48d52baec1a1 100644
--- a/drivers/media/rc/ir_toy.c
+++ b/drivers/media/rc/ir_toy.c@@ -24,6 +24,7 @@ static const u8 COMMAND_VERSION[] = { 'v' }; // End transmit and repeat reset command so we exit sump mode static const u8 COMMAND_RESET[] = { 0xff, 0xff, 0, 0, 0, 0, 0 }; static const u8 COMMAND_SMODE_ENTER[] = { 's' }; +static const u8 COMMAND_SMODE_EXIT[] = { 0 }; static const u8 COMMAND_TXSTART[] = { 0x26, 0x24, 0x25, 0x03 }; #define REPLY_XMITCOUNT 't'
@@ -309,12 +310,30 @@ static int irtoy_tx(struct rc_dev *rc, uint *txbuf, uint count) buf[i] = cpu_to_be16(v); } - buf[count] = cpu_to_be16(0xffff); + buf[count] = 0xffff; irtoy->tx_buf = buf; irtoy->tx_len = size; irtoy->emitted = 0; + // There is an issue where if the unit is receiving IR while the + // first TXSTART command is sent, the device might end up hanging + // with its led on. It does not respond to any command when this + // happens. To work around this, re-enter sample mode. + err = irtoy_command(irtoy, COMMAND_SMODE_EXIT, + sizeof(COMMAND_SMODE_EXIT), STATE_RESET); + if (err) { + dev_err(irtoy->dev, "exit sample mode: %d\n", err); + return err; + } + + err = irtoy_command(irtoy, COMMAND_SMODE_ENTER, + sizeof(COMMAND_SMODE_ENTER), STATE_COMMAND); + if (err) { + dev_err(irtoy->dev, "enter sample mode: %d\n", err); + return err; + } + err = irtoy_command(irtoy, COMMAND_TXSTART, sizeof(COMMAND_TXSTART), STATE_TX); kfree(buf);