Messages in this thread | | | Subject | Re: Issue with RTL8111 NIC after upgrade to kernel 4.19 | From | Heiner Kallweit <> | Date | Wed, 21 Nov 2018 21:52:17 +0100 |
| |
On 21.11.2018 21:49, Heiner Kallweit wrote: > On 21.11.2018 21:32, Heiner Kallweit wrote: >> On 21.11.2018 21:20, Andrew Lunn wrote: >>>> request_module() is supposed to be synchronous, however after some >>>> reading this may not be 100% guaranteed. Maybe the module init >>>> function on some systems isn't finished yet when request_module() >>>> returns. As a result the genphy driver may be used instead of >>>> the PHY version-specific driver. >>> >>> Hi Heiner >>> >>> That would be true for all PHYs i think. We would of noticed this >>> problem with other systems using other PHY drivers. >>> >>> Andrew >>> >> It could be a timing issue affecting certain systems only. At least >> for now I don't have a good explanation why loading the module via >> request_module() and loading it upfront manually makes a difference. >> >> One affected user just reported the PHY to be a RTL8211B. This is >> what I expected, because this PHY crashes when writing to the MMD >> registers (the MMD registers are used otherwise by this PHY). >> See also commit 0231b1a074c6 ("net: phy: realtek: Use the dummy >> stubs for MMD register access for rtl8211b"). >> >> Let's see whether the other affected systems use the same PHY >> version. >> > Next report is also about a RTL8211B and as I assumed: > - W/o manually loading the realtek module the genphy driver is used > and network fails. > - W/ manually loading the realtek module the proper RTL8211B PHY > driver is used and network works. > > So it seems that even after request_module() the PHY driver isn't > yet available when device and driver are matched. > > If further reports support this (pre-)analysis, then indeed it > seems to be a timing issue and a proper fix most likely is > difficult. As a workaround I could imagine to add a delay loop > after request_module() checking for a Realtek PHY driver via > driver_find(). When adding one small delay after this we should > be sufficiently sure that all Realtek PHY drivers are registered. > Uups, no. We talk about phylib here, not about the r8169 driver. So we need a different solution.
>> Heiner >> >
| |