diff options
| author | Sean Young <sean@mess.org> | 2022-01-13 21:53:51 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2022-01-24 01:38:32 +0100 |
| commit | 6a554bb5653f9844c2ee179d91a757b28ec36a99 (patch) | |
| tree | 0571d0630ec0bc57e49b461a08b9bef82de6b62d /drivers/media/rc | |
| parent | 1ad09bbf8458298f224eea04e44507bccbe8b229 (diff) | |
| download | linux-6a554bb5653f9844c2ee179d91a757b28ec36a99.tar.bz2 | |
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: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Diffstat (limited to 'drivers/media/rc')
| -rw-r--r-- | drivers/media/rc/mtk-cir.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/drivers/media/rc/mtk-cir.c b/drivers/media/rc/mtk-cir.c index 746d43fdc17a..1255e3afb032 100644 --- a/drivers/media/rc/mtk-cir.c +++ b/drivers/media/rc/mtk-cir.c @@ -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++) { |