[PATCH 5.15 011/230] can: m_can: m_can_{read_fifo,echo_tx_event}(): shift timestamp to full 32 bits

Greg Kroah-Hartman
2022-07-11T09:38:23Z

From: Marc Kleine-Budde <mkl@pengutronix.de>

commit 4c3333693f07313f5f0145a922f14a7d3c0f4f21 upstream.

In commit 1be37d3b0414 ("can: m_can: fix periph RX path: use
rx-offload to ensure skbs are sent from softirq context") the RX path
for peripheral devices was switched to RX-offload.

Received CAN frames are pushed to RX-offload together with a
timestamp. RX-offload is designed to handle overflows of the timestamp
correctly, if 32 bit timestamps are provided.

The timestamps of m_can core are only 16 bits wide. So this patch
shifts them to full 32 bit before passing them to RX-offload.

Link: https://lore.kernel.org/all/20220612211410.4081390-1-mkl@pengutronix.de
Fixes: 1be37d3b0414 ("can: m_can: fix periph RX path: use rx-offload to ensure skbs are sent from softirq context")
Cc: <stable@vger.kernel.org> # 5.13
Cc: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Reviewed-by: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/can/m_can/m_can.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -532,7 +532,7 @@ static int m_can_read_fifo(struct net_de
stats->rx_packets++;
stats->rx_bytes += cf->len;

- timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc);
+ timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;

m_can_receive_skb(cdev, skb, timestamp);

@@ -1043,7 +1043,7 @@ static int m_can_echo_tx_event(struct ne
}

msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
- timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe);
+ timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;

/* ack txe element */
m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,