From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
Cc: bjorn.andersson@linaro.org, ohad@wizery.com,
loic.pallardy@st.com, s-anna@ti.com,
linux-remoteproc@vger.kernel.org, corbet@lwn.net,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 11/14] remoteproc: Deal with synchronisation when changing FW image
Date: Thu, 30 Apr 2020 14:32:05 -0600 [thread overview]
Message-ID: <20200430203205.GA18004@xps15> (raw)
In-Reply-To: <4ab6d7ac-905b-494e-cce7-cb8a697decb7@st.com>
On Wed, Apr 29, 2020 at 10:52:48AM +0200, Arnaud POULIQUEN wrote:
>
>
> On 4/24/20 10:01 PM, Mathieu Poirier wrote:
> > This patch prevents the firmware image from being displayed or changed
> > when the remoteproc core is synchronising with a remote processor. This
> > is needed since there is no guarantee about the nature of the firmware
> > image that is loaded by the external entity.
> >
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> > ---
> > drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++-
> > 1 file changed, 23 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> > index 7f8536b73295..cdd322a6ecfa 100644
> > --- a/drivers/remoteproc/remoteproc_sysfs.c
> > +++ b/drivers/remoteproc/remoteproc_sysfs.c
> > @@ -13,9 +13,20 @@
> > static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
> > char *buf)
> > {
> > + ssize_t ret;
> > struct rproc *rproc = to_rproc(dev);
> >
> > - return sprintf(buf, "%s\n", rproc->firmware);
> > + /*
> > + * In most instances there is no guarantee about the firmware
> > + * that was loaded by the external entity. As such simply don't
> > + * print anything.
> > + */
> > + if (rproc_needs_syncing(rproc))
> > + ret = sprintf(buf, "\n");
>
> A default name is provided in sysfs if no firmware is started/synchronised on boot.
>
> IMO providing an empty name here could be confusing.
> Perhaps a refactoring of this sysfs entry would be nice:
> - Normal boot (no firmware loaded) : empty name instead of a default name
That is guaranteed to break user space so we can't proceed this way.
> - auto_boot: name provided by the platform driver or default name ( current implementation)
> - synchronization: a predefined name such as Default, unknown, External, None,...
Loic had the same comment. Usually it is best to provide sysfs output that
don't need parsing, i.e 0/1 or nothing at all, but in the remoteproc subsystem
we already have "state", "name" and "firmware" that need parsing. As such my
next revision will have "unknown", which I think is the best way to describe the
situation.
>
> > + else
> > + ret = sprintf(buf, "%s\n", rproc->firmware);
> > +
> > + return ret;
> > }
> >
> > /* Change firmware name via sysfs */
> > @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev,
> > goto out;
> > }
> >
> > + /*
> > + * There is no point in trying to change the firmware if loading the
> > + * image of the remote processor is done by another entity.
> > + */
> > + if (rproc_needs_syncing(rproc)) {
> > + dev_err(dev,
> > + "can't change firmware while synchronising with MCU\n");
>
> I don't know if you decide to keep "MCU" or not. If not the case
> you have also some other instances in your patch 9/14.
MCU should be long gone. I thought I had spotted them all but was obviously
wrong.
>
> Regards
> Arnaud
>
> > + err = -EBUSY;
> > + goto out;
> > + }
> > +
> > len = strcspn(buf, "\n");
> > if (!len) {
> > dev_err(dev, "can't provide a NULL firmware\n");
> >
next prev parent reply other threads:[~2020-04-30 20:32 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 20:01 [PATCH v3 00/14] remoteproc: Add support for synchronisaton with rproc Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 01/14] remoteproc: Make core operations optional Mathieu Poirier
2020-04-28 16:18 ` Arnaud POULIQUEN
2020-04-30 19:39 ` Mathieu Poirier
2020-05-05 22:16 ` Bjorn Andersson
2020-05-08 19:09 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 02/14] remoteproc: Introduce function rproc_alloc_internals() Mathieu Poirier
2020-05-05 22:31 ` Bjorn Andersson
2020-05-08 19:37 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 03/14] remoteproc: Add new operation and flags for synchronistation Mathieu Poirier
2020-04-28 16:38 ` Arnaud POULIQUEN
2020-04-30 19:49 ` Mathieu Poirier
2020-05-06 0:22 ` Bjorn Andersson
2020-05-08 21:01 ` Mathieu Poirier
2020-05-14 1:32 ` Bjorn Andersson
2020-05-15 19:24 ` Mathieu Poirier
2020-05-19 0:55 ` Bjorn Andersson
2020-05-20 22:06 ` Mathieu Poirier
2020-05-21 5:21 ` Bjorn Andersson
2020-05-21 21:55 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 04/14] remoteproc: Refactor function rproc_boot() Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 05/14] remoteproc: Refactor function rproc_fw_boot() Mathieu Poirier
2020-05-06 0:33 ` Bjorn Andersson
2020-05-08 21:27 ` Mathieu Poirier
2020-05-14 2:10 ` Bjorn Andersson
2020-05-15 19:46 ` Mathieu Poirier
2020-05-19 0:22 ` Bjorn Andersson
2020-04-24 20:01 ` [PATCH v3 06/14] remoteproc: Refactor function rproc_trigger_auto_boot() Mathieu Poirier
2020-04-28 17:00 ` Arnaud POULIQUEN
2020-04-24 20:01 ` [PATCH v3 07/14] remoteproc: Introducting new start and stop functions Mathieu Poirier
2020-05-06 0:42 ` Bjorn Andersson
2020-04-24 20:01 ` [PATCH v3 08/14] remoteproc: Call core functions based on synchronisation flag Mathieu Poirier
2020-04-28 17:27 ` Arnaud POULIQUEN
2020-04-30 19:57 ` Mathieu Poirier
2020-05-04 11:14 ` Arnaud POULIQUEN
2020-05-05 22:10 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 09/14] remoteproc: Deal with synchronisation when crashing Mathieu Poirier
2020-04-29 7:44 ` Arnaud POULIQUEN
2020-04-30 20:11 ` Mathieu Poirier
2020-05-06 1:01 ` Bjorn Andersson
2020-05-08 21:47 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 10/14] remoteproc: Deal with synchronisation when shutting down Mathieu Poirier
2020-04-29 8:19 ` Arnaud POULIQUEN
2020-04-30 20:23 ` Mathieu Poirier
2020-05-04 11:34 ` Arnaud POULIQUEN
2020-05-05 22:03 ` Mathieu Poirier
2020-05-06 7:51 ` Arnaud POULIQUEN
2020-05-06 1:10 ` Bjorn Andersson
2020-04-24 20:01 ` [PATCH v3 11/14] remoteproc: Deal with synchronisation when changing FW image Mathieu Poirier
2020-04-29 8:52 ` Arnaud POULIQUEN
2020-04-30 20:32 ` Mathieu Poirier [this message]
2020-05-06 1:27 ` Bjorn Andersson
2020-04-24 20:01 ` [PATCH v3 12/14] remoteproc: Introducing function rproc_set_state_machine() Mathieu Poirier
2020-04-29 9:22 ` Arnaud POULIQUEN
2020-04-29 14:38 ` Arnaud POULIQUEN
2020-04-30 20:51 ` Mathieu Poirier
2020-05-04 12:00 ` Arnaud POULIQUEN
2020-04-30 20:42 ` Mathieu Poirier
2020-05-04 11:57 ` Arnaud POULIQUEN
2020-05-05 21:43 ` Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 13/14] remoteproc: Document " Mathieu Poirier
2020-04-24 20:01 ` [PATCH v3 14/14] remoteproc: Expose synchronisation flags via debugfs Mathieu Poirier
2020-05-18 13:28 ` [PATCH v3 00/14] remoteproc: Add support for synchronisaton with rproc Peng Fan
2020-05-18 16:29 ` Mathieu Poirier
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