Hi Geert,
> -----Original Message-----
> From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Sent: 22 August 2025 10:51
> To: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>; Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>; Biju Das
> <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: linux-can@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx; Geert Uytterhoeven
> <geert+renesas@xxxxxxxxx>
> Subject: [PATCH/RFC 6/6] can: rcar_canfd: Add suspend/resume support
>
> On R-Car Gen3 using PSCI, s2ram powers down the SoC. After resume, the CAN-FD interface no longer
> works. Trying to bring it up again fails:
>
> # ip link set can0 up
> RTNETLINK answers: Connection timed out
>
> # dmesg
> ...
> channel 0 communication state failed
>
> Fix this by populating the (currently empty) suspend and resume callbacks, to stop/start the individual
> CAN-FD channels, and (de)initialize the CAN-FD controller.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> While this fixes CAN-FD after resume from s2ram on R-Car E3 (Ebisu-4D), it does introduce a regression
> on R-Car V4H (White Hawk): after resume from s2idle (White Hawk does not support s2ram), CAN frames
> sent by other devices are no longer received, and the other side sometimes reports a "bus-off".
>
> However, the underlying issue is pre-existing, and can be reproduced without this patch: the CAN-FD
> controller fails in the same way after driver unbind/rebind. So something must be missing in the
> (de)initialization sequence for the R-Car Gen4 CAN-FD register layout.
> Note that it keeps on working after ifdown/ifup, which does not reinitialize the full controller.
> ---
> drivers/net/can/rcar/rcar_canfd.c | 53 +++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
> index eedce83b91414c57..6b0c563e894f74b3 100644
> --- a/drivers/net/can/rcar/rcar_canfd.c
> +++ b/drivers/net/can/rcar/rcar_canfd.c
> @@ -2236,11 +2236,64 @@ static void rcar_canfd_remove(struct platform_device *pdev)
>
> static int rcar_canfd_suspend(struct device *dev) {
> + struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
> + int err;
> + u32 ch;
> +
> + for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
> + struct rcar_canfd_channel *priv = gpriv->ch[ch];
> + struct net_device *ndev = priv->ndev;
> +
> + if (!netif_running(ndev))
> + continue;
> +
> + netif_device_detach(ndev);
> +
> + err = rcar_canfd_close(ndev);
> + if (err) {
> + netdev_err(ndev, "rcar_canfd_close() failed %pe\n",
> + ERR_PTR(err));
> + return err;
> + }
> +
> + priv->can.state = CAN_STATE_SLEEPING;
> + }
> +
> + /* TODO Skip if wake-up (which is not yet supported) is enabled */
> + rcar_canfd_global_deinit(gpriv, false);
> +
> return 0;
> }
>
> static int rcar_canfd_resume(struct device *dev) {
> + struct rcar_canfd_global *gpriv = dev_get_drvdata(dev);
> + int err;
> + u32 ch;
> +
> + err = rcar_canfd_global_init(gpriv);
> + if (err) {
> + dev_err(dev, "rcar_canfd_open() failed %pe\n", ERR_PTR(err));
> + return err;
> + }
> +
> + for_each_set_bit(ch, &gpriv->channels_mask, gpriv->info->max_channels) {
> + struct rcar_canfd_channel *priv = gpriv->ch[ch];
> + struct net_device *ndev = priv->ndev;
> +
> + if (!netif_running(ndev))
> + continue;
> +
> + err = rcar_canfd_open(ndev);
> + if (err) {
> + netdev_err(ndev, "rcar_canfd_open() failed %pe\n",
> + ERR_PTR(err));
> + return err;
> + }
> +
> + netif_device_attach(ndev);
> + }
> +
> return 0;
> }
>
This patch does not work on RZ/G3E, please see the logs
Bind/Unbind:
-------------
root@smarc-rzg3e:/cip-test-scripts# cd /sys/bus/platform/drivers/rcar_canfd
n > unbindroot@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo 12440000.can > unbind
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo 12440000.can > bind
[ 67.645615] rcar_canfd 12440000.can: can_clk rate is 80000000
[ 67.655044] rcar_canfd 12440000.can: device registered (channel 1)
[ 67.661788] rcar_canfd 12440000.can: can_clk rate is 80000000
[ 67.671258] rcar_canfd 12440000.can: device registered (channel 4)
[ 67.677603] rcar_canfd 12440000.can: global operational state (canfd clk, fd mode)
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# /cip-test-scripts/canfd_t_003.sh
[INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
[INFO] Testing can0<->can1 with bitrate 500000 and dbitrate 2000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
[INFO] Testing can0<->can1 with bitrate 250000 and dbitrate 1000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
EXIT|PASS|canfd_t_003.sh|[00:00:25] ||
G3E S2Idle:
------------
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo s2idle > /sys/power/mem_sleep
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo mem > /sys/power/state
[ 160.231921] PM: suspend entry (s2idle)
[ 160.236099] Filesystems sync: 0.000 seconds
[ 160.248409] Freezing user space processes
[ 160.255200] Freezing user space processes completed (elapsed 0.002 seconds)
[ 160.262354] OOM killer disabled.
[ 160.265681] Freezing remaining freezable tasks
[ 160.271723] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[ 160.279253] printk: Suspending console(s) (use no_console_suspend to debug)
[ 160.311505] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 160.377382] renesas-gbeth 15c30000.ethernet end0: Link is Down
[ 162.226309] dwmac4: Master AXI performs fixed burst length
[ 162.227718] renesas-gbeth 15c30000.ethernet end0: No Safety Features support found
[ 162.227788] renesas-gbeth 15c30000.ethernet end0: IEEE 1588-2008 Advanced Timestamp supported
[ 162.232919] renesas-gbeth 15c30000.ethernet end0: configuring for phy/rgmii-id link mode
[ 162.252982] dwmac4: Master AXI performs fixed burst length
[ 162.254258] renesas-gbeth 15c40000.ethernet end1: No Safety Features support found
[ 162.254321] renesas-gbeth 15c40000.ethernet end1: IEEE 1588-2008 Advanced Timestamp supported
[ 162.259706] renesas-gbeth 15c40000.ethernet end1: configuring for phy/rgmii-id link mode
[ 162.307564] usb usb1: root hub lost power or was reset
[ 162.307607] usb usb2: root hub lost power or was reset
[ 164.471610] usb 2-1: reset SuperSpeed Plus Gen 2x1 USB device number 2 using xhci-renesas-hcd
[ 164.584382] OOM killer enabled.
[ 164.587540] Restarting tasks: Starting
[ 164.593757] Restarting tasks: Done
[ 164.597263] random: crng reseeded on system resumption
[ 164.602497] PM: suspend exit
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# [ 164.959424] renesas-gbeth 15c30000.ethernet end0: Link is Up - 1Gbps/Full - flow control rx/tx
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# /cip-test-scripts/canfd_t_003.sh
[INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
[INFO] Testing can0<->can1 with bitrate 500000 and dbitrate 2000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
[INFO] Testing can0<->can1 with bitrate 250000 and dbitrate 1000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
[INFO] Testing can0 as producer and can1 as consumer
EXIT|PASS|canfd_t_003.sh|[00:00:25] ||
G3E STR:
--------
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo deep > /sys/power/mem_sleep
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# echo mem > /sys/power/state
[ 237.863858] PM: suspend entry (deep)
[ 237.867860] Filesystems sync: 0.000 seconds
[ 237.878623] Freezing user space processes
[ 237.885330] Freezing user space processes completed (elapsed 0.002 seconds)
[ 237.892455] OOM killer disabled.
[ 237.895804] Freezing remaining freezable tasks
[ 237.902064] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[ 237.909648] printk: Suspending console(s) (use no_console_suspend to debug)
NOTICE: BL2: v2.10.5(release):2.10.5/rz_soc_dev-169-g1410189b0
NOTICE: BL2: Built : 12:53:12, Jul 15 2025
NOTICE: BL2: SYS_LSI_MODE: 0x13e06
NOTICE: BL2: SYS_LSI_DEVID: 0x8679447
NOTICE: BL2: SYS_LSI_PRR: 0x0
NOTICE: BL2: Booting BL31
[ 237.943571] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 237.992789] renesas-gbeth 15c30000.ethernet end0: Link is Down
[ 238.006388] Disabling non-boot CPUs ...
[ 238.011104] psci: CPU3 killed (polled 0 ms)
[ 238.017799] psci: CPU2 killed (polled 0 ms)
[ 238.023704] psci: CPU1 killed (polled 4 ms)
[ 238.028259] Enabling non-boot CPUs ...
[ 238.028474] Detected VIPT I-cache on CPU1
[ 238.028521] GICv3: CPU1: found redistributor 100 region 0:0x0000000014960000
[ 238.028558] CPU1: Booted secondary processor 0x0000000100 [0x412fd050]
[ 238.029374] CPU1 is up
[ 238.029470] Detected VIPT I-cache on CPU2
[ 238.029492] GICv3: CPU2: found redistributor 200 region 0:0x0000000014980000
[ 238.029513] CPU2: Booted secondary processor 0x0000000200 [0x412fd050]
[ 238.030046] CPU2 is up
[ 238.030145] Detected VIPT I-cache on CPU3
[ 238.030167] GICv3: CPU3: found redistributor 300 region 0:0x00000000149a0000
[ 238.030189] CPU3: Booted secondary processor 0x0000000300 [0x412fd050]
[ 238.030873] CPU3 is up
[ 238.047257] dwmac4: Master AXI performs fixed burst length
[ 238.048165] renesas-gbeth 15c30000.ethernet end0: No Safety Features support found
[ 238.048185] renesas-gbeth 15c30000.ethernet end0: IEEE 1588-2008 Advanced Timestamp supported
[ 238.051680] renesas-gbeth 15c30000.ethernet end0: configuring for phy/rgmii-id link mode
[ 238.069106] dwmac4: Master AXI performs fixed burst length
[ 238.070002] renesas-gbeth 15c40000.ethernet end1: No Safety Features support found
[ 238.070018] renesas-gbeth 15c40000.ethernet end1: IEEE 1588-2008 Advanced Timestamp supported
[ 238.073613] renesas-gbeth 15c40000.ethernet end1: configuring for phy/rgmii-id link mode
[ 238.119909] usb usb1: root hub lost power or was reset
[ 238.119918] usb usb2: root hub lost power or was reset
[ 240.279309] usb 2-1: reset SuperSpeed Plus Gen 2x1 USB device number 2 using xhci-renesas-hcd
[ 240.468214] OOM killer enabled.
[ 240.471358] Restarting tasks: Starting
[ 240.475721] Restarting tasks: Done
[ 240.479171] random: crng reseeded on system resumption
[ 240.484426] PM: suspend exit
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# [ 240.692426] renesas-gbeth 15c30000.ethernet end0: Link is Up - 1Gbps/Full - flow control rx/tx
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd#
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd# /cip-test-scripts/canfd_t_003.sh
[INFO] Testing can0<->can1 with bitrate 1000000 and dbitrate 4000000
[INFO] Bringing down can0 can1
[INFO] Bringing up can0 can1
[INFO] Testing can1 as producer and can0 as consumer
EXIT|FAIL|canfd_t_003.sh|[00:00:04] Problems while producing data from can1 and consuming from can0||
root@smarc-rzg3e:/sys/bus/platform/drivers/rcar_canfd#
