Re: [PATCH 1/4] remoteproc: Introduce always-on flag

From: loic pallardy
Date: Tue Aug 02 2016 - 11:19:57 EST


Hi Bjorn,

On 08/01/2016 08:58 PM, Bjorn Andersson wrote:
Introduce an "always-on" flag on rprocs to make it possible to flag
remote processors without vdevs to automatically boot once the firmware
is found.

Should this flag rather be named "auto-boot"? From my pov, "always-on" means coprocessor can't be shutdown.

Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Cc: Loic Pallardy <loic.pallardy@xxxxxx>
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
drivers/remoteproc/remoteproc_core.c | 27 ++++++++++++++++++++++++++-
drivers/remoteproc/remoteproc_virtio.c | 13 -------------
include/linux/remoteproc.h | 1 +
3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index fe0539ed9cb5..7e7f24fcac69 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -933,6 +933,10 @@ static void rproc_fw_config_virtio(const struct firmware *fw, void *context)
/* look for virtio devices and register them */
ret = rproc_handle_resources(rproc, tablesz, rproc_vdev_handler);

+ /* if rproc is marked always-on, request it to boot */
+ if (rproc->always_on)
+ rproc_boot_nowait(rproc);
+
out:
release_firmware(fw);
/* allow rproc_del() contexts, if any, to proceed */
@@ -978,11 +982,16 @@ static int rproc_add_virtio_devices(struct rproc *rproc)
int rproc_trigger_recovery(struct rproc *rproc)
{
struct rproc_vdev *rvdev, *rvtmp;
+ int ret;

dev_err(&rproc->dev, "recovering %s\n", rproc->name);

init_completion(&rproc->crash_comp);

+ /* shut down the remote */
+ /* TODO: make sure this works with rproc->power > 1 */
+ rproc_shutdown(rproc);
+
/* clean up remote vdev entries */
list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node)
rproc_remove_virtio_dev(rvdev);
@@ -993,7 +1002,17 @@ int rproc_trigger_recovery(struct rproc *rproc)
/* Free the copy of the resource table */
kfree(rproc->cached_table);

- return rproc_add_virtio_devices(rproc);
+ ret = rproc_add_virtio_devices(rproc);
+ if (ret)
+ return ret;
+
+ /*
+ * boot the remote processor up again, waiting for the async fw load to
+ * finish
+ */
+ rproc_boot(rproc);
You are changing current behavior by forcing rproc boot whatever "always-on". Moreover coprocessor already rebooted by rproc_add_virtio_device if "always-on" flag is set, doesn't it?
If yes, rproc->power will be equal to 2 and rproc_shutdown call will failed as this second rproc_boot call is unknown from customer pov.

Regards,
Loic

+
+ return 0;
}

/**
@@ -1374,6 +1393,7 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
rproc->name = name;
rproc->ops = ops;
rproc->priv = &rproc[1];
+ rproc->always_on = true;

device_initialize(&rproc->dev);
rproc->dev.parent = dev;
@@ -1452,6 +1472,11 @@ int rproc_del(struct rproc *rproc)
/* if rproc is just being registered, wait */
wait_for_completion(&rproc->firmware_loading_complete);

+ /* if rproc is marked always-on, rproc_add() booted it */
+ /* TODO: make sure this works with rproc->power > 1 */
+ if (rproc->always_on)
+ rproc_shutdown(rproc);
+
/* clean up remote vdev entries */
list_for_each_entry_safe(rvdev, tmp, &rproc->rvdevs, node)
rproc_remove_virtio_dev(rvdev);
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index cc91556313e1..574c90ce07f7 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -136,11 +136,6 @@ static void __rproc_virtio_del_vqs(struct virtio_device *vdev)

static void rproc_virtio_del_vqs(struct virtio_device *vdev)
{
- struct rproc *rproc = vdev_to_rproc(vdev);
-
- /* power down the remote processor before deleting vqs */
- rproc_shutdown(rproc);
-
__rproc_virtio_del_vqs(vdev);
}

@@ -149,7 +144,6 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
vq_callback_t *callbacks[],
const char * const names[])
{
- struct rproc *rproc = vdev_to_rproc(vdev);
int i, ret;

for (i = 0; i < nvqs; ++i) {
@@ -160,13 +154,6 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
}
}

- /* now that the vqs are all set, boot the remote processor */
- ret = rproc_boot_nowait(rproc);
- if (ret) {
- dev_err(&rproc->dev, "rproc_boot() failed %d\n", ret);
- goto error;
- }
-
return 0;

error:
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 1c457a8dd5a6..bd1cfcbb57b9 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -443,6 +443,7 @@ struct rproc {
struct resource_table *cached_table;
u32 table_csum;
bool has_iommu;
+ bool always_on;
};

/* we currently support only two vrings per rvdev */