From: Mark A. Greer Date: Tue, 2 Sep 2014 22:12:31 +0000 (-0700) Subject: NFC: trf7970a: Reread FIFO Status Register when draining FIFO X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=5d8f759424d3d7da998a7a9eee702071c8e5d381;p=deliverable%2Flinux.git NFC: trf7970a: Reread FIFO Status Register when draining FIFO Receiving an interrupt whose Interrupt Status Register value has only the SRX bit set is supposed to mean that all of the data from the tag has been received. That turns out to not be true so we need to reread the FIFO Status Register to tell if there are any new bytes in the FIFO. If there are, continue receiving them; if there aren't, assume that the receive is complete and pass the data up. Signed-off-by: Mark A. Greer Signed-off-by: Samuel Ortiz --- diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c index 6d2b06ddf191..8c00827893f1 100644 --- a/drivers/nfc/trf7970a.c +++ b/drivers/nfc/trf7970a.c @@ -648,6 +648,21 @@ static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status) status = TRF7970A_IRQ_STATUS_SRX; } else { trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT; + + ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + return; + } + + fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW; + + /* If there are bytes in the FIFO, set status to '0' so + * the if stmt below doesn't fire and the driver will wait + * for the trf7970a to generate another RX interrupt. + */ + if (fifo_bytes) + status = 0; } no_rx_data: