> -----Original Message----- > From: Jon Hunter <jonathanh@xxxxxxxxxx> > Sent: 2021年3月30日 20:51 > To: Joakim Zhang <qiangqing.zhang@xxxxxxx> > Cc: netdev@xxxxxxxxxxxxxxx; Linux Kernel Mailing List > <linux-kernel@xxxxxxxxxxxxxxx>; linux-tegra <linux-tegra@xxxxxxxxxxxxxxx>; > Jakub Kicinski <kuba@xxxxxxxxxx> > Subject: Re: Regression v5.12-rc3: net: stmmac: re-init rx buffers when mac > resume back > > > > On 25/03/2021 08:12, Joakim Zhang wrote: > > ... > > >>>>> You mean one of your boards? Does other boards with STMMAC can > >>>>> work > >>>> fine? > >>>> > >>>> We have two devices with the STMMAC and one works OK and the other > >> fails. > >>>> They are different generation of device and so there could be some > >>>> architectural differences which is causing this to only be seen on one > device. > >>> It's really strange, but I also don't know what architectural > >>> differences could > >> affect this. Sorry. > > > I realised that for the board which fails after this change is made, it has the > IOMMU enabled. The other board does not at the moment (although work is in > progress to enable). If I add 'iommu.passthrough=1' to cmdline for the failing > board, then it works again. So in my case, the problem is linked to the IOMMU > being enabled. > > Does you platform enable the IOMMU? Hi Jon, There is no IOMMU hardware available on our boards. But why IOMMU would affect it during suspend/resume, and no problem in normal mode? Best Regards, Joakim Zhang > Thanks > Jon > > -- > nvpublic
