On Fri, May 17, 2019 at 08:16:34AM -0700, Alexander Duyck wrote: > On Thu, May 16, 2019 at 6:48 PM Florian Fainelli <f.faine...@gmail.com> wrote: > > > > > > > > On 5/16/2019 6:03 PM, Daniel Walker wrote: > > > On Thu, May 16, 2019 at 03:02:18PM -0700, Florian Fainelli wrote: > > >> On 5/16/19 12:55 PM, Nikunj Kela (nkela) wrote: > > >>> > > >>> > > >>> On 5/16/19, 12:35 PM, "Jeff Kirsher" <jeffrey.t.kirs...@intel.com> > > >>> wrote: > > >>> > > >>> On Wed, 2019-05-08 at 23:14 +0000, Nikunj Kela wrote: > > >>> >> Some of the broken NICs don't have EEPROM programmed correctly. It > > >>> >> results > > >>> >> in probe to fail. This change adds a module parameter that can be > > >>> >> used to > > >>> >> ignore nvm checksum validation. > > >>> >> > > >>> >> Cc: xe-linux-exter...@cisco.com > > >>> >> Signed-off-by: Nikunj Kela <nk...@cisco.com> > > >>> >> --- > > >>> >> drivers/net/ethernet/intel/igb/igb_main.c | 28 > > >>> >> ++++++++++++++++++++++------ > > >>> >> 1 file changed, 22 insertions(+), 6 deletions(-) > > >>> > > >>> >NAK for two reasons. First, module parameters are not desirable > > >>> >because their individual to one driver and a global solution > > >>> should be > > >>> >found so that all networking device drivers can use the solution. > > >>> This > > >>> >will keep the interface to change/setup/modify networking drivers > > >>> >consistent for all drivers. > > >>> > > >>> > > >>> >Second and more importantly, if your NIC is broken, fix it. Do > > >>> not try > > >>> >and create a software workaround so that you can continue to use a > > >>> >broken NIC. There are methods/tools available to properly > > >>> reprogram > > >>> >the EEPROM on a NIC, which is the right solution for your issue. > > >>> > > >>> I am proposing this as a debug parameter. Obviously, we need to fix > > >>> EEPROM but this helps us continuing the development while manufacturing > > >>> fixes NIC. > > >> > > >> Then why even bother with sending this upstream? > > > > > > It seems rather drastic to disable the entire driver because the checksum > > > doesn't match. It really should be a warning, even a big warning, to let > > > people > > > know something is wrong, but disabling the whole driver doesn't make > > > sense. > > > > You could generate a random Ethernet MAC address if you don't have a > > valid one, a lot of drivers do that, and that's a fairly reasonable > > behavior. At some point in your product development someone will > > certainly verify that the provisioned MAC address matches the network > > interface's MAC address. > > -- > > Florian > > The thing is the EEPROM contains much more than just the MAC address. > There ends up being configuration for some of the PCIe interface in > the hardware as well as PHY configuration. If that is somehow mangled > we shouldn't be bringing up the part because there are one or more > pieces of the device configuration that are likely wrong. > > The checksum is being used to make sure the EEPROM is valid, without > that we would need to go through and validate each individual section > of the EEPROM before enabling the the portions of the device related > to it. The concern is that this will become a slippery slope where we > eventually have to code all the configuration of the EEPROM into the > driver itself.
I don't think you can say because the checksum is valid that all data contained inside is also valid. You can have a valid checksum , and someone screwed up the data prior to the checksum getting computed. > We need to make the checksum a hard stop. If the part is broken then > it needs to be addressed. Workarounds just end up being used and > forgotten, which makes it that much harder to support the product. > Better to mark the part as being broken, and get it fixed now, than to > have parts start shipping that require workarounds in order to > function.o I don't think it's realistic to define the development process for large corporations like Cisco, or like what your doing , to define the development process for all corporations and products which may use intel parts. It's better to be flexible. Daniel
