The patch below does not apply to the 5.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4114978dcd24e72415276bba60ff4ff355970bbc Mon Sep 17 00:00:00 2001

From: Sean Young sean@mess.org Date: Tue, 14 Sep 2021 16:57:46 +0200 Subject: [PATCH] media: ir_toy: prevent device from hanging during transmit

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 [mchehab: renamed: s/STATE_RESET/STATE_COMMAND_NO_RESP/ ] Signed-off-by: Sean Young sean@mess.org Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org

diff --git a/drivers/media/rc/ir_toy.c b/drivers/media/rc/ir_toy.c index d2d9346eb8f5..71aced52248f 100644 --- a/drivers/media/rc/ir_toy.c +++ b/drivers/media/rc/ir_toy.c @@ -26,6 +26,7 @@ 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' @@ -317,12 +318,30 @@ 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_COMMAND_NO_RESP); + 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);