Hi Paul
On 14/12/2019 11:30 PM, Paul Cercueil wrote:
> Hi Fabien,
>
>
> Le jeu., déc. 12, 2019 at 10:03, Fabien DESSENNE
> <fabien.dessenne@xxxxxx> a écrit :
>> Hi Paul
>>
>>
>> On 10/12/2019 5:40 PM, Paul Cercueil wrote:
>>> The .prepare() callback is called before the firmware is loaded to
>>> memory. This is useful for instance in the case where some setup is
>>> required for the memory to be accessible.
>>
>>
>> I am trying to figure out what king of 'setup' may be required. From the
>> ingenic driver I understand that you need to enable clocks to allow some
>> memory access.
>>
>> Instead of adding this new ops, why not enabling clocks in probe()?
>
> Enabling the clocks in the probe means that the clocks will be
> unconditionally enabled until the driver is removed, even if the
> remote processor end up being unused. That would be a waste of power.
OK I understand.
Nevertheless I think that you may need to call .prepare() from
rproc_fw_boot() since you may need to access some memories from the
point rproc_handle_resources() is called (this sets up virtio which is
used if you have a resource table defining vdev).
And rproc_fw_boot() calls rproc_enable_iommu(), which sounds like
"prepare memory", so this may be the right place to call .prepare()
BR
Fabien
>
> Cheers,
> -Paul
>
>
>>
>> BR
>>
>> Fabien
>>
>>
>>>
>>> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
>>> ---
>>>
>>> Notes:
>>> v2-v4: No change
>>>
>>> drivers/remoteproc/remoteproc_core.c | 16 +++++++++++++++-
>>> include/linux/remoteproc.h | 4 ++++
>>> 2 files changed, 19 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/remoteproc/remoteproc_core.c
>>> b/drivers/remoteproc/remoteproc_core.c
>>> index 0a9fc7fdd1c3..3ea5f675a148 100644
>>> --- a/drivers/remoteproc/remoteproc_core.c
>>> +++ b/drivers/remoteproc/remoteproc_core.c
>>> @@ -1299,11 +1299,19 @@ static int rproc_start(struct rproc *rproc,
>>> const struct firmware *fw)
>>> struct device *dev = &rproc->dev;
>>> int ret;
>>>
>>> + if (rproc->ops->prepare) {
>>> + ret = rproc->ops->prepare(rproc);
>>> + if (ret) {
>>> + dev_err(dev, "Failed to prepare rproc: %d\n", ret);
>>> + return ret;
>>> + }
>>> + }
>>> +
>>> /* load the ELF segments to memory */
>>> ret = rproc_load_segments(rproc, fw);
>>> if (ret) {
>>> dev_err(dev, "Failed to load program segments: %d\n", ret);
>>> - return ret;
>>> + goto unprepare_rproc;
>>> }
>>>
>>> /*
>>> @@ -1354,6 +1362,9 @@ static int rproc_start(struct rproc *rproc,
>>> const struct firmware *fw)
>>> rproc_unprepare_subdevices(rproc);
>>> reset_table_ptr:
>>> rproc->table_ptr = rproc->cached_table;
>>> +unprepare_rproc:
>>> + if (rproc->ops->unprepare)
>>> + rproc->ops->unprepare(rproc);
>>>
>>> return ret;
>>> }
>>> @@ -1483,6 +1494,9 @@ static int rproc_stop(struct rproc *rproc,
>>> bool crashed)
>>>
>>> rproc->state = RPROC_OFFLINE;
>>>
>>> + if (rproc->ops->unprepare)
>>> + rproc->ops->unprepare(rproc);
>>> +
>>> dev_info(dev, "stopped remote processor %s\n", rproc->name);
>>>
>>> return 0;
>>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>>> index 5f201f0c86c3..a6272d1ba384 100644
>>> --- a/include/linux/remoteproc.h
>>> +++ b/include/linux/remoteproc.h
>>> @@ -355,6 +355,8 @@ enum rsc_handling_status {
>>>
>>> /**
>>> * struct rproc_ops - platform-specific device handlers
>>> + * @prepare: prepare the device for power up (before the
>>> firmware is loaded)
>>> + * @unprepare: unprepare the device after it is stopped
>>> * @start: power on the device and boot it
>>> * @stop: power off the device
>>> * @kick: kick a virtqueue (virtqueue id given as a parameter)
>>> @@ -371,6 +373,8 @@ enum rsc_handling_status {
>>> * @get_boot_addr: get boot address to entry point specified
>>> in firmware
>>> */
>>> struct rproc_ops {
>>> + int (*prepare)(struct rproc *rproc);
>>> + void (*unprepare)(struct rproc *rproc);
>>> int (*start)(struct rproc *rproc);
>>> int (*stop)(struct rproc *rproc);
>>> void (*kick)(struct rproc *rproc, int vqid);
>
>
