Hi, On Wed, Jun 18, 2014 at 01:11:27AM +0100, Mark Brown wrote: > On Tue, Jun 17, 2014 at 09:36:35PM +0200, Markus Pargmann wrote: > > > To enable writing of registers through the regmap debugfs interface, it > > was necessary to alter the regmap-debugfs.c source code. This is not > > really practical. > > > As this is a powerful tool for debugging, this patch creates an expert > > kconfig option for this function. This makes it easier to enable > > register writing in the kernel. > > This is deliberately hard to enable in order to make it clear that it > should never, ever be used in production as a bodge around writing > drivers and generally in order to reduce the risk to the rest of the > system. Enabling this will typically give userspace full access to > components like PMICs which have the potential to cause physical damage > to the system if misused.
The userspace already has full access to all those registers if you want. For example memory mapped registeres can be written through /dev/mem. I2C registers can easily be changed using i2c-tools or the /dev/i2c-* devices. So you are already able to write a userspace driver if you really want to. I think this kconfig option would make it easier to debug hardware or driver issues, as it is much more comfortable to have a clean kconfig option. > > Anyone with a use for this is most likely building their own kernels > anyway and if a user modifies the code to enable it is clear that it is > their responsibility to deal with the fallout. > > > This patch also fixes the file mode when the regmap debugfs write code is > > compiled. > > Seperate changes in separate patches, especially don't put bugfixes in > the same patch as features. Ok, I will split this to a seperate patch Thanks, Markus -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
signature.asc
Description: Digital signature
