Hi Lorenzo, Thanks a lot for your comments!
> -----Original Message----- > From: Lorenzo Pieralisi <[email protected]> > Sent: 2019年6月12日 1:18 > To: Z.q. Hou <[email protected]>; [email protected] > Cc: [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; Leo Li <[email protected]>; > [email protected]; [email protected]; Mingkai Hu > <[email protected]>; M.h. Lian <[email protected]>; Xiaowei Bao > <[email protected]> > Subject: Re: [PATCHv5 16/20] PCI: mobiveil: Add link up condition check > > NB: Please trim the CC list and keep it to concerned maintainers. > > On Fri, Apr 12, 2019 at 08:36:48AM +0000, Z.q. Hou wrote: > > From: Hou Zhiqiang <[email protected]> > > > > Avoid to issue CFG transactions to link partner when the PCIe link is > > not up. > > > > Signed-off-by: Hou Zhiqiang <[email protected]> > > --- > > V5: > > - Corrected the subject. > > > > drivers/pci/controller/pcie-mobiveil.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/pci/controller/pcie-mobiveil.c > > b/drivers/pci/controller/pcie-mobiveil.c > > index 621852078caf..1ee3ea2570c0 100644 > > --- a/drivers/pci/controller/pcie-mobiveil.c > > +++ b/drivers/pci/controller/pcie-mobiveil.c > > @@ -283,6 +283,10 @@ static bool mobiveil_pcie_valid_device(struct > > pci_bus *bus, unsigned int devfn) { > > struct mobiveil_pcie *pcie = bus->sysdata; > > > > + /* If there is no link, then there is no device */ > > + if (bus->number > pcie->root_bus_nr && !mobiveil_pcie_link_up(pcie)) > > I think Bjorn mentioned this a million times already, eg: > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.ke > rnel.org%2Flinux-pci%2F20190411201535.GS256045%40google.com%2F&am > p;data=02%7C01%7Czhiqiang.hou%40nxp.com%7Cffb4c8dcebe4493a375908 > d6ee90b471%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63695 > 8702637973543&sdata=m%2FqV5zohqyBMUDT7zrVjF%2FLtYeJZO36rdY > eMTPGGbHg%3D&reserved=0 > > this is racy and gives a false sense of robustness. We have code in the kernel > that checks the link but adding more seems silly to me, so I am inclined to > drop this patch. > Understand, drop it. Thanks, Zhiqiang > Lorenzo > > > + return false; > > + > > /* Only one device down on each root port */ > > if ((bus->number == pcie->root_bus_nr) && (devfn > 0)) > > return false; > > -- > > 2.17.1 > >
