> -----Original Message----- > From: Thomas Monjalon <tho...@monjalon.net> > Sent: Friday, July 17, 2020 18:06 > To: Slava Ovsiienko <viachesl...@mellanox.com> > Cc: dev@dpdk.org; Matan Azrad <ma...@mellanox.com>; Raslan > Darawsheh <rasl...@mellanox.com> > Subject: Re: [PATCH 3/3] common/mlx5: fix DevX register access opcode > > 17/07/2020 16:28, Viacheslav Ovsiienko: > > The dedicated MLX5_CMD_OP_ACCESS_REGISTER_USER opcode must be > used to > > read hardware register content from unprotected mode. > > Otherwise? What was broken?
Otherwise the MLX5_CMD_OP_ACCESS_REGISTER was used, it returned EINVAL and register value was not read. It was supposed to enable ACCESS_REGISTER operation from user mode in kernel driver to read registers, but eventually it was replaced with ACCESS_REGISTER_USER dedicated operation. mlx5 PMD does not rely on this feature strongly, if register reading fails it deduces the timestamp mode from reported timestamp counter frequency. With best regards, Slava
