Hi Suman,
On Thu, Mar 05, 2020 at 04:41:08PM -0600, Suman Anna wrote:
> The commit 086d08725d34 ("remoteproc: create vdev subdevice with specific
> dma memory pool") has introduced a new vdev subdevice for each vdev
> declared in the firmware resource table and made it as the parent for the
> created virtio rpmsg devices instead of the previous remoteproc device.
> This changed the overall parenting hierarchy for the rpmsg devices, which
> were children of virtio devices, and does not allow the corresponding
> rpmsg drivers to retrieve the parent rproc device through the
> rproc_get_by_child() API.
>
> Fix this by restoring the remoteproc device as the parent. The new vdev
> subdevice can continue to inherit the DMA attributes from the remoteproc's
> parent device (actual platform device).
>
> Fixes: 086d08725d34 ("remoteproc: create vdev subdevice with specific dma memory pool")
> Signed-off-by: Suman Anna <s-anna@xxxxxx>
> ---
> drivers/remoteproc/remoteproc_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 097f33e4f1f3..ba18f32bd0c4 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -510,7 +510,7 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>
> /* Initialise vdev subdevice */
> snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
> - rvdev->dev.parent = rproc->dev.parent;
> + rvdev->dev.parent = &rproc->dev;
I can see how it would not be possible to retrieve the parent rproc device since
rvdev->dev.parent was set to be platform device...
I wonder how the original change didn't blow up sysmon_probe() and potentially
other out-of-tree users of rproc_get_by_child(). It would be nice to have
someone from the QCOM team test your patch.
> rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
> rvdev->dev.release = rproc_rvdev_release;
> dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
Be mindful there might be fallouts from applying this patch since it does change
the location of the vdev under /sys/device/platform/ .
Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> --
> 2.23.0
>
