From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
Cc: Rishabh Bhatnagar <rishabhb@codeaurora.org>,
"linux-remoteproc@vger.kernel.org"
<linux-remoteproc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"tsoni@codeaurora.org" <tsoni@codeaurora.org>,
"psodagud@codeaurora.org" <psodagud@codeaurora.org>,
"sidgup@codeaurora.org" <sidgup@codeaurora.org>
Subject: Re: [PATCH v6 0/3] Move recovery/coredump configuration to sysfs
Date: Tue, 29 Sep 2020 09:33:57 -0500 [thread overview]
Message-ID: <20200929143357.GE10036@builder.lan> (raw)
In-Reply-To: <8222f5fa-2acc-a765-a728-6aad9ed88068@st.com>
On Tue 29 Sep 03:44 CDT 2020, Arnaud POULIQUEN wrote:
>
>
> On 9/29/20 12:17 AM, Rishabh Bhatnagar wrote:
> > From Android R onwards Google has restricted access to debugfs in user
> > and user-debug builds. This restricts access to most of the features
> > exposed through debugfs. 'Coredump' and 'Recovery' are critical
> > interfaces that are required for remoteproc to work on Qualcomm Chipsets.
> > Coredump configuration needs to be set to "inline" in debug/test builds
> > and "disabled" in production builds. Whereas recovery needs to be
> > "disabled" for debugging purposes and "enabled" on production builds.
> > This patch series removes the recovery/coredump entries from debugfs
> > and moves them to sysfs. Also, this disables the coredump collection
> > by default as this is a requirement for production devices.
> >
> > Changelog:
> >
> > v6 -> v5:
> > - Disable coredump collection by default
> > - Rename the "default" configuration to "enabled" to avoid confusion
> >
> > v5 -> v4:
> > - Fix the cover-letter of tha patch series.
> >
> > v4 -> v3:
> > - Remove the feature flag to expose recovery/coredump
> >
> > v3 -> v2:
> > - Remove the coredump/recovery entries from debugfs
>
> Sorry i missed this and some associated discussion in V2...
>
> I have also some concerns about the ABI breaks.
Debugfs is not an ABI...
> In ST and I suppose in several companies we have some
> test environments that use the debugfs to generate and/or get
> the core dump.
>
I do however acknowledge the inconvenience you're facing...
> Even if the stability of the debugfs is not guaranteed it would
> be nice to keep both interface.
>
...and I wouldn't mind keeping the debugfs interface around, at least
for some time to allow people to transition their tools/muscle memory.
> It seems that it is possible to create symbolic link in the debugfs
> thanks to the "debugfs_create_symlink" function.
> This seems allowing to keep files in both place without duplicating the code.
> To be honest i have never used this function so I'm not 100% sure that this
> would do the job...
> But if you think that this could be a good compromise, i can test it.
>
The duplicated code is rather simple, so I don't mind the duplication -
for now.
So, how about we add the sysfs pieces of Rishabh's patches, leave out
the debugfs and then in a while (e.g. one LTS) we remove the debugfs
code?
Regards,
Bjorn
> Regards,
> Arnaud
>
> > - Expose recovery/coredump from sysfs under a feature flag
> >
> > v1 -> v2:
> > - Correct the contact name in the sysfs documentation.
> > - Remove the redundant write documentation for coredump/recovery sysfs
> > - Add a feature flag to make this interface switch configurable.
> >
> > Rishabh Bhatnagar (3):
> > remoteproc: Move coredump configuration to sysfs
> > remoteproc: Move recovery configuration to sysfs
> > remoteproc: Change default dump configuration to "disabled"
> >
> > Documentation/ABI/testing/sysfs-class-remoteproc | 46 +++++++
> > drivers/remoteproc/remoteproc_coredump.c | 6 +-
> > drivers/remoteproc/remoteproc_debugfs.c | 168 -----------------------
> > drivers/remoteproc/remoteproc_sysfs.c | 120 ++++++++++++++++
> > include/linux/remoteproc.h | 8 +-
> > 5 files changed, 173 insertions(+), 175 deletions(-)
> >
next prev parent reply other threads:[~2020-09-29 14:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-28 22:17 [PATCH v6 0/3] Move recovery/coredump configuration to sysfs Rishabh Bhatnagar
2020-09-28 22:17 ` [PATCH v6 1/3] remoteproc: Move coredump " Rishabh Bhatnagar
2020-09-29 3:24 ` Bjorn Andersson
2020-09-28 22:17 ` [PATCH v6 2/3] remoteproc: Move recovery " Rishabh Bhatnagar
2020-09-30 8:11 ` Arnaud POULIQUEN
2020-09-30 8:58 ` Arnaud POULIQUEN
2020-09-28 22:17 ` [PATCH v6 3/3] remoteproc: Change default dump configuration to "disabled" Rishabh Bhatnagar
2020-09-29 8:44 ` [PATCH v6 0/3] Move recovery/coredump configuration to sysfs Arnaud POULIQUEN
2020-09-29 14:33 ` Bjorn Andersson [this message]
2020-09-29 17:18 ` Arnaud POULIQUEN
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