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(-) > >
