On Fri, Jul 31, 2026 at 4:24 PM Miao Wang <[email protected]> wrote: > > Hi, > > > 2026年7月31日 16:07，Huacai Chen <[email protected]> 写道： > > > > On Fri, Jul 24, 2026 at 5:28 PM Miao Wang <[email protected]> wrote: > >> > >> Hi, > >> > >>> 2026年7月24日 16:55，Huacai Chen <[email protected]> 写道： > >>> > >>> Hi, Miao, > >>> > >>> On Fri, Jul 10, 2026 at 1:24 AM Miao Wang via B4 Relay > >>> <[email protected]> wrote: > >>>> > >>>> Previously, the driver has been introduced to support the Loongson 2K > >>>> BMC running on the Loongson Servers, which is essential to prevent > >>>> the system from hanging when the BMC is being reset and the default > >>>> efi-framebuffer is being used. However, there are some drawbacks in the > >>>> driver. > >>>> > >>>> Firstly, the driver tries to read and write to the connected PCI-E host > >>>> controller registers, assuming that the BMC is connected to LS7A PCI-E > >>>> host controller. This assumption should be true for real products, but > >>>> to prevent from accidentally reading and writing to the wrong PCI-E host > >>>> controller, this driver should be modified to check this before > >>>> accessing the registers. > >>>> > >>>> Secondly, the driver uses non-exported functions to tell the vt > >>>> subsystem to redraw the screen, preventing the driver from being > >>>> compiling as a module. This can be fixed by using the exported > >>>> functions instead. > >>> You can replace the redraw function, but I don't think it is necessary > >>> to make the bmc driver modular. > >>> > >>> BMC core, IPMI and simpledrm display are usually (if not always) > >>> supposed to work as early as possible. > >> > >> I believe that it should be the user's decision to choose whether to > >> compile a module into the kernel or as a module and it would be better > >> if we can provide the possibilities for the user to choose from. > >> Additionally, I don't think these modules are supposed to work that > >> early. The mfd module provide two functions, the display and the ipmi > >> device. In the aspect of graphical display, without this module, the > >> user can still see the output during booting on their monitors, since > >> efifb is working, providing a basic display function. In the aspect of > >> the ipmi device, I don't think the lack of such device will influence > >> the boot of the system, since it is a common practice to compile ipmi > >> device drivers as modules on other architectures. As a result, neither > >> of the two functions are required to be loaded that early and it is > >> reasonable to at lease leave the choice to compile it as a module > >> to the user. > > Flexibility is not always useful, if a config doesn't provide good > > effect, then it just increases complexity and makes maintenance more > > difficult. > > I should emphasize that to allow this driver to be a module, there is > no such increase on maintenance. Moreover, not all loongarch machines > are requiring this driver. Especially only a part of the server models > are quipped with this BMC. Comparing with other architectures, the > driver for BMC are normally compiled as a module, such as mgag200 for > iLO from HPE and iDRAC from DELL, hibmc_drm for Kunpeng server from > Huawei. None of these BMC drivers requiring to be compiled into the > kernel. I cannot see there is any reason keeping the driver from being > allowed to be compiled as a module. I also do not think it will bring > any significant maintenance burden. Implementing correct cleanup code > should be necessary instead of burden. Can we split into two series, one fix bugs and the others make bmc modular?
Otherwise I don't think we can reach a consensus in the near future. Huacai > > Cheers, > > Miao Wang > > _______________________________________________ Openipmi-developer mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openipmi-developer
