From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org,
linux-can@vger.kernel.org, kernel@pengutronix.de,
Thomas Kopp <thomas.kopp@microchip.com>
Subject: Re: [net 21/27] can: mcp251xfd: mcp251xfd_regmap_crc_read(): increase severity of CRC read error messages
Date: Thu, 5 Nov 2020 23:44:53 +0530 [thread overview]
Message-ID: <20201105181453.GJ7308@work> (raw)
In-Reply-To: <cee3b960-6633-bffd-d1a6-05e4a5e20b2e@pengutronix.de>
On Thu, Nov 05, 2020 at 05:39:31PM +0100, Marc Kleine-Budde wrote:
> On 11/5/20 5:24 PM, Manivannan Sadhasivam wrote:
> > Hi Marc,
> >
> > On Tue, Nov 03, 2020 at 11:06:30PM +0100, Marc Kleine-Budde wrote:
> >> During debugging it turned out that some people have setups where the SPI
> >> communication is more prone to CRC errors.
> >>
> >> Increase the severity of both the transfer retry and transfer failure message
> >> to give users feedback without the need to recompile the driver with debug
> >> enabled.
> >>
> >> Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> >> Cc: Thomas Kopp <thomas.kopp@microchip.com>
> >> Link: http://lore.kernel.org/r/20201019190524.1285319-15-mkl@pengutronix.de
> >> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> >> ---
> >> drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c | 16 ++++++++--------
> >> 1 file changed, 8 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
> >> index ba25902dd78c..c9ffc5ea2b25 100644
> >> --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
> >> +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
> >> @@ -330,17 +330,17 @@ mcp251xfd_regmap_crc_read(void *context,
> >> goto out;
> >> }
> >>
> >> - netdev_dbg(priv->ndev,
> >> - "CRC read error at address 0x%04x (length=%zd, data=%*ph, CRC=0x%04x) retrying.\n",
> >> - reg, val_len, (int)val_len, buf_rx->data,
> >> - get_unaligned_be16(buf_rx->data + val_len));
> >> - }
> >> -
> >> - if (err) {
> >> netdev_info(priv->ndev,
> >> - "CRC read error at address 0x%04x (length=%zd, data=%*ph, CRC=0x%04x).\n",
> >> + "CRC read error at address 0x%04x (length=%zd, data=%*ph, CRC=0x%04x) retrying.\n",
> >> reg, val_len, (int)val_len, buf_rx->data,
> >> get_unaligned_be16(buf_rx->data + val_len));
> >
> > I'm not finding this inner debug log useful. Does the user really care
> > about the iterations it took to read a register? Just throwing the error
> > after max try seems better to me.
>
> Bitflips on the SPI should not happen, at least not regularly. Even with my
> breadboard setup and max SPI frequency, I don't see any SPI CRC errors, unless
> there is bad cabling. Then a retry most of the times helps and the user doesn't
> notice. This drops performance...Yes logging drop performance, too, but at least
> someone will notice.
>
> My rationale was to give the user feedback and not cover a potential problem.
> The driver is new and probably not widely used and I have no idea how often it
> runs into read-CRC problems in production use.
>
Okay. Let's see if anyone complain ;)
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Thanks,
Mani
> Marc
>
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Embedded Linux | https://www.pengutronix.de |
> Vertretung West/Dortmund | Phone: +49-231-2826-924 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
>
next prev parent reply other threads:[~2020-11-05 18:15 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 22:06 pull-request: can 2020-11-03 Marc Kleine-Budde
2020-11-03 22:06 ` [net 01/27] dt-bindings: can: add can-controller.yaml Marc Kleine-Budde
2020-11-03 22:06 ` [net 02/27] dt-bindings: can: flexcan: convert fsl,*flexcan bindings to yaml Marc Kleine-Budde
2020-11-03 22:06 ` [net 03/27] can: proc: can_remove_proc(): silence remove_proc_entry warning Marc Kleine-Budde
2020-11-03 22:06 ` [net 04/27] can: rx-offload: don't call kfree_skb() from IRQ context Marc Kleine-Budde
2020-11-03 22:06 ` [net 05/27] can: dev: can_get_echo_skb(): prevent call to kfree_skb() in hard " Marc Kleine-Budde
2020-11-04 1:21 ` Jakub Kicinski
2020-11-04 4:29 ` Vincent MAILHOL
2020-11-04 8:16 ` Eric Dumazet
2020-11-04 14:59 ` Oliver Hartkopp
2020-11-04 16:02 ` Jakub Kicinski
2020-11-04 17:46 ` Oliver Hartkopp
2020-11-05 4:47 ` Vincent MAILHOL
2020-11-05 7:44 ` Marc Kleine-Budde
2020-11-03 22:06 ` [net 06/27] can: dev: __can_get_echo_skb(): fix real payload length return value for RTR frames Marc Kleine-Budde
2020-11-03 22:06 ` [net 07/27] can: can_create_echo_skb(): fix echo skb generation: always use skb_clone() Marc Kleine-Budde
2020-11-03 22:06 ` [net 08/27] can: j1939: rename jacd tool Marc Kleine-Budde
2020-11-03 22:06 ` [net 09/27] can: j1939: fix syntax and spelling Marc Kleine-Budde
2020-11-03 22:06 ` [net 10/27] can: j1939: swap addr and pgn in the send example Marc Kleine-Budde
2020-11-03 22:06 ` [net 11/27] can: j1939: use backquotes for code samples Marc Kleine-Budde
2020-11-03 22:06 ` [net 12/27] can: j1939: j1939_sk_bind(): return failure if netdev is down Marc Kleine-Budde
2020-11-03 22:06 ` [net 13/27] can: isotp: Explain PDU in CAN_ISOTP help text Marc Kleine-Budde
2020-11-03 22:06 ` [net 14/27] can: isotp: isotp_rcv_cf(): enable RX timeout handling in listen-only mode Marc Kleine-Budde
2020-11-03 22:06 ` [net 15/27] can: isotp: padlen(): make const array static, makes object smaller Marc Kleine-Budde
2020-11-03 22:06 ` [net 16/27] can: ti_hecc: ti_hecc_probe(): add missed clk_disable_unprepare() in error path Marc Kleine-Budde
2020-11-03 22:06 ` [net 17/27] can: xilinx_can: handle failure cases of pm_runtime_get_sync Marc Kleine-Budde
2020-11-03 22:06 ` [net 18/27] can: peak_usb: add range checking in decode operations Marc Kleine-Budde
2020-11-03 22:06 ` [net 19/27] can: peak_usb: peak_usb_get_ts_time(): fix timestamp wrapping Marc Kleine-Budde
2020-11-03 22:06 ` [net 20/27] can: peak_canfd: pucan_handle_can_rx(): fix echo management when loopback is on Marc Kleine-Budde
2020-11-03 22:06 ` [net 21/27] can: mcp251xfd: mcp251xfd_regmap_crc_read(): increase severity of CRC read error messages Marc Kleine-Budde
2020-11-05 16:24 ` Manivannan Sadhasivam
2020-11-05 16:39 ` Marc Kleine-Budde
2020-11-05 18:14 ` Manivannan Sadhasivam [this message]
2020-11-06 8:35 ` Marc Kleine-Budde
2020-11-03 22:06 ` [net 22/27] can: mcp251xfd: mcp251xfd_regmap_nocrc_read(): fix semicolon.cocci warnings Marc Kleine-Budde
2020-11-03 22:06 ` [net 23/27] can: mcp251xfd: remove unneeded break Marc Kleine-Budde
2020-11-03 22:06 ` [net 24/27] can: flexcan: remove FLEXCAN_QUIRK_DISABLE_MECR quirk for LS1021A Marc Kleine-Budde
2020-11-03 22:06 ` [net 25/27] can: flexcan: add ECC initialization for LX2160A Marc Kleine-Budde
2020-11-03 22:06 ` [net 26/27] can: flexcan: add ECC initialization for VF610 Marc Kleine-Budde
2020-11-03 22:06 ` [net 27/27] can: flexcan: flexcan_remove(): disable wakeup completely Marc Kleine-Budde
2020-11-04 18:43 ` pull-request: can 2020-11-03 Jakub Kicinski
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