Hi Ulf, On Thu, May 08, 2025 at 12:03:33PM +0200, Ulf Hansson wrote: >On Wed, 7 May 2025 at 18:02, Hiago De Franco <hiagofra...@gmail.com> wrote: >> >> From: Hiago De Franco <hiago.fra...@toradex.com> >> >> When the remote core is started before Linux boots (e.g., by the >> bootloader), the driver currently is not able to attach because it only >> checks for cores running in different partitions. If the core was kicked >> by the bootloader, it is in the same partition as Linux and it is >> already up and running. >> >> This adds power mode verification through the SCU interface, enabling >> the driver to detect when the remote core is already running and >> properly attach to it. >> >> Signed-off-by: Hiago De Franco <hiago.fra...@toradex.com> >> Suggested-by: Peng Fan <peng....@nxp.com> >> --- >> v2: Dropped unecessary include. Removed the imx_rproc_is_on function, as >> suggested. >> --- >> drivers/remoteproc/imx_rproc.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c >> index 627e57a88db2..9b6e9e41b7fc 100644 >> --- a/drivers/remoteproc/imx_rproc.c >> +++ b/drivers/remoteproc/imx_rproc.c >> @@ -949,6 +949,19 @@ static int imx_rproc_detect_mode(struct imx_rproc *priv) >> if (of_property_read_u32(dev->of_node, >> "fsl,entry-address", &priv->entry)) >> return -EINVAL; >> >> + /* >> + * If remote core is already running (e.g. kicked by >> + * the bootloader), attach to it. >> + */ >> + ret = >> imx_sc_pm_get_resource_power_mode(priv->ipc_handle, >> + >> priv->rsrc_id); >> + if (ret < 0) >> + dev_err(dev, "failed to get power resource >> %d mode, ret %d\n", >> + priv->rsrc_id, ret); >> + >> + if (ret == IMX_SC_PM_PW_MODE_ON) >> + priv->rproc->state = RPROC_DETACHED; >> + >> return imx_rproc_attach_pd(priv); > >Why is it important to potentially set "priv->rproc->state = >RPROC_DETACHED" before calling imx_rproc_attach_pd()? > >Would it be possible to do it the other way around? First calling >imx_rproc_attach_pd() then get the power-mode to know if >RPROC_DETACHED should be set or not?
If M4 is not powered up by bootloader, attach_pd is to power up the related power domains. And the rproc->state should be OFFLINE. If M4 is powered up by bootloader, the rproc->state should be set as DETACHED, then attach_pd here will not touch the real pd, because scu-pd driver set is_off as false when doing pm_genpd_init. In this case, we still need attach_pd to avoid power shutdown when pd_ignore_unused and also need to support linux stop/start m4 even it is started by bootloader. So we could not reverse the logic. Regards, Peng > >The main reason why I ask, is because of how we handle the single PM >domain case. In that case, the PM domain has already been attached >(and powered-on) before we reach this point. > >> } >> >> -- >> 2.39.5 >> > >Kind regards >Uffe
