Re: [PATCH V5 2/2] remoteproc: support attach recovery after rproc crash

From: Mathieu Poirier
Date: Wed Jun 22 2022 - 13:25:38 EST


On Wed, Jun 15, 2022 at 11:20:48AM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
>
> Current logic only support main processor to stop/start the remote
> processor after rproc crash. However to SoC, such as i.MX8QM/QXP, the
> remote processor could do attach recovery after crash and trigger watchdog
> reboot. It does not need main processor to load image, or stop/start M4
> core.
>
> Introduce two functions: rproc_attach_recovery, rproc_firmware_recovery
> for the two cases. Firmware recovery is as before, let main processor to
> help recovery, while attach recovery is recover itself withou help.
> To attach recovery, we only do detach and attach.
>
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/remoteproc/remoteproc_core.c | 64 +++++++++++++++++++---------
> 1 file changed, 45 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 02a04ab34a23..1c1c90176aff 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1883,6 +1883,47 @@ static int __rproc_detach(struct rproc *rproc)
> return 0;
> }
>
> +static int rproc_attach_recovery(struct rproc *rproc)
> +{
> + int ret;
> +
> + mutex_unlock(&rproc->lock);
> + ret = __rproc_detach(rproc);
> + mutex_lock(&rproc->lock);
> + if (ret)
> + return ret;
> +
> + return __rproc_attach(rproc);
> +}
> +
> +static int rproc_firmware_recovery(struct rproc *rproc)

s/rproc_firmware_recovery/rproc_boot_recovery

> +{
> + const struct firmware *firmware_p;
> + struct device *dev = &rproc->dev;
> + int ret;
> +
> + ret = rproc_stop(rproc, true);
> + if (ret)
> + return ret;
> +
> + /* generate coredump */
> + rproc->ops->coredump(rproc);
> +
> + /* load firmware */
> + ret = request_firmware(&firmware_p, rproc->firmware, dev);
> + if (ret < 0) {
> + dev_err(dev, "request_firmware failed: %d\n", ret);
> + return ret;
> + }
> +
> + /* boot the remote processor up again */
> + ret = rproc_start(rproc, firmware_p);
> +
> + release_firmware(firmware_p);
> +
> + return ret;
> +}
> +
> /**
> * rproc_trigger_recovery() - recover a remoteproc
> * @rproc: the remote processor
> @@ -1897,7 +1938,6 @@ static int __rproc_detach(struct rproc *rproc)
> */
> int rproc_trigger_recovery(struct rproc *rproc)
> {
> - const struct firmware *firmware_p;
> struct device *dev = &rproc->dev;
> int ret;
>
> @@ -1911,24 +1951,10 @@ int rproc_trigger_recovery(struct rproc *rproc)
>
> dev_err(dev, "recovering %s\n", rproc->name);
>
> - ret = rproc_stop(rproc, true);
> - if (ret)
> - goto unlock_mutex;
> -
> - /* generate coredump */
> - rproc->ops->coredump(rproc);
> -
> - /* load firmware */
> - ret = request_firmware(&firmware_p, rproc->firmware, dev);
> - if (ret < 0) {
> - dev_err(dev, "request_firmware failed: %d\n", ret);
> - goto unlock_mutex;
> - }
> -
> - /* boot the remote processor up again */
> - ret = rproc_start(rproc, firmware_p);
> -
> - release_firmware(firmware_p);
> + if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
> + ret = rproc_attach_recovery(rproc);
> + else
> + ret = rproc_firmware_recovery(rproc);

This patch contains a serious flaw related to locking that should have been
obvious when it was put together. Please go back and carefully review the code you are submitting.

I will not consider another revision of this set until July 15th.

Thanks,
Mathieu

>
> unlock_mutex:
> mutex_unlock(&rproc->lock);
> --
> 2.25.1
>