On Wed, Dec 7, 2016 at 12:45 AM, Stephen Hemminger <step...@networkplumber.org> wrote: > On Wed, 7 Dec 2016 00:33:08 +0200 > Saeed Mahameed <sae...@mellanox.com> wrote: > >> This simple ethool change will give HW vendors the flexibility to set >> pure HW configurations (not directly related to netdev resources states >> and rings), without the need of vendor proprietary tools and hacks. > > > The danger is you need to restrict the kernel to only allow setting > safe registers (and this is HW dependent). There are cases like secure > boot where it is expected that even root is not allowed to modify > all memory. > > Also supporting closed format of device registers is not in the interest > of promoting open source. >
This is not totally close format, it is only a generic API to support setting some of the HW registers. the format is open in 1. http://www.mellanox.com/related-docs/user_manuals/Ethernet_Adapters_Programming_Manual.pdf 2. http://lxr.free-electrons.com/source/include/linux/mlx5/mlx5_ifc.h We just want to let the user to configure HW dependent registers without the need to add new defines/callback each time to the kernel ABI/API. > I am not saying I fundamentally disagree with supporting this, but it > is a bigger step than you make it out to be. I have to disagree, it is not as big as it seems, there are already at least two places in ethtool API that do the same, http://lxr.free-electrons.com/source/include/linux/ethtool.h 192 * @set_eeprom: Write data to the device EEPROM. 193 * Should validate the magic field. Don't need to check len for zero 194 * or wraparound. Update len to the amount written. Returns an error 195 * or zero. http://lxr.free-electrons.com/source/net/core/ethtool.c#L1582 234 * @flash_device: Write a firmware image to device's flash memory. 235 * Returns a negative error code or zero. Both accept a binary array from user and forward to HW/FW. Simply we want to to the same for HW registers, you already have a way to get them (even parse them in user ethtool), but you can't set them.
