Commit 6a554bb5 authored by Sean Young's avatar Sean Young Committed by Mauro Carvalho Chehab
Browse files

media: mtk-cir: remove superfluous ir_raw_event_reset() 



This IR receiver has two limitations:

1) Any IR pulse or space longer than 12ms will be truncated to 12ms

2) Any pulses/spaces after the first 68 are lost

ir_raw_event_reset() won't help here. If the IR cannot be decoded, any
decoder should reset itself, and if it does not, this is a bug in the
decoder.

Cc: Sean Wang <sean.wang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 1ad09bbf

drivers/media/rc/mtk-cir.c

+11 −12
Original line number Diff line number Diff line
@@ -209,19 +209,18 @@ static irqreturn_t mtk_ir_irq(int irqno, void *dev_id) 
	struct ir_raw_event rawir = {};



	/*

	 * Reset decoder state machine explicitly is required

	 * because 1) the longest duration for space MTK IR hardware

	 * could record is not safely long. e.g  12ms if rx resolution

	 * is 46us by default. There is still the risk to satisfying

	 * every decoder to reset themselves through long enough

	 * trailing spaces and 2) the IRQ handler guarantees that

	 * start of IR message is always contained in and starting

	 * from register mtk_chkdata_reg(ir, i).

	 * Each pulse and space is encoded as a single byte, each byte

	 * alternating between pulse and space. If a pulse or space is longer

	 * than can be encoded in a single byte, it is encoded as the maximum

	 * value 0xff.

	 *

	 * If a space is longer than ok_count (about 23ms), the value is

	 * encoded as zero, and all following bytes are zero. Any IR that

	 * follows will be presented in the next interrupt.

	 *

	 * If there are more than 68 (=MTK_CHKDATA_SZ * 4) pulses and spaces,

	 * then the only the first 68 will be presented; the rest is lost.

	 */

	ir_raw_event_reset(ir->rc);



	/* First message must be pulse */

	rawir.pulse = false;



	/* Handle all pulse and space IR controller captures */

	for (i = 0 ; i < MTK_CHKDATA_SZ ; i++) {