On Tue, 2017-08-29 at 09:53 +0000, Xiaowei Bao wrote: > Hi, > > This solution is got by discuss with minghuan and zhiqiang, according to the > customer's response to this problem in the uboot period, when the kernel will > not exist after the start of the problem. Because if the uboot scan the pcie > device, the kernel also find this device. >
But this does not solve my problem and the solution is only for layerscape ATM. I am asking FSL PCI guys if we could just rewrite the old ltssm >= L0 test to something more sane that will work for me and the rest of FSL u-boot/linux users. > Thanks > > > -----Original Message----- > From: Joakim Tjernlund [mailto:joakim.tjernl...@infinera.com] > Sent: Tuesday, August 29, 2017 2:45 PM > To: Xiaowei Bao <xiaowei....@nxp.com>; York Sun <york....@nxp.com> > Cc: u-boot@lists.denx.de > Subject: Re: FSL PCIe LTSSM >= PCI_LTSSM_L0 equals link up > > On Tue, 2017-08-29 at 03:19 +0000, Xiaowei Bao wrote: > > Hi York, > > > > > + if (ltssm == LTSSM_PCIE_DETECT_QUIET || > > > + ltssm == LTSSM_PCIE_DETECT_ACTIVE) { > > > > When the pcie slot have no device, the pcie controller access this register > > return LTSSM_PCIE_DETECT_QUIET or LTSSM_PCIE_DETECT_ACTIVE state, In order > > to avoid unnecessary delay, return directly. > > > > Reference the spec, except L0 state, the L0s L1 L2state can consider the > > link state, but these state regards the power management, our pcie driver > > have not power management code in uboot, so just need to judge the L0 state. > > > > But Linux has power mgmt(I guess this is ASPM?). Could we come up with a new > test that work for both Linux and u-boot ? Is the LTSSM reg. standardized for > all FSL PCIe controllers? > > Jocke > > > Thanks > > > > -----Original Message----- > > From: York Sun > > Sent: Tuesday, August 29, 2017 1:15 AM > > To: Xiaowei Bao <xiaowei....@nxp.com> > > Cc: Joakim Tjernlund <joakim.tjernl...@infinera.com>; > > u-boot@lists.denx.de > > Subject: Re: FSL PCIe LTSSM >= PCI_LTSSM_L0 equals link up > > > > +Xiaowei > > > > On 08/28/2017 10:09 AM, Joakim Tjernlund wrote: > > > On Mon, 2017-08-28 at 16:55 +0000, York Sun wrote: > > > > On 08/28/2017 09:48 AM, Joakim Tjernlund wrote: > > > > > FSL PCIe controller drivers before REV 3 has this test for link up: > > > > > enabled = ltssm >= PCI_LTSSM_L0; > > > > > > > > > > We have a PCIe dev. that stays in LTSSM=0x51 (Polling > > > > > Compliance) when non ready for PCI transaktions. When FSL PCIe > > > > > controller tries to access this device, it hangs forever. > > > > > > > > > > Is LTSSM=0x51 really a "legal" state for link up? > > > > > If not, what is a suitable range(maybe LO <= ltssm <= L0s(0x27)) ? > > > > > > > > > > Jocke > > > > > > > > > > BTW, the same test is valid in Linux too. > > > > > > > > > > > > > Jocke, > > > > > > > > I am not an expert on PCIe. Please if this thread is helpful, > > > > > > Me neither .. :) > > > > > > > > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpatchwork.ozlabs.org%2Fpatch%2F801519%2F&data=01%7C01%7Cyork.sun%40nxp.com%7Cf46ff5111ba04e631a9b08d4ee377ecc%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0&sdata=n9%2B2NIjEvsMBCljRLHS6NVVN4ANa3nBGpwUjI4Od%2Bhs%3D&reserved=0. > > > > > > It mentions polling compliance but this driver already tests for: > > > if (ltssm < LTSSM_PCIE_L0) > > > return 0; > > > return 1; > > > > > > It just adds some delay if the device is in Polling Compliance to > > > see if that changes to L0. > > > Since both layerscape and fsl >= rev 3 already require ltssm to be > > > == L0, I suspect the ltssm >= L0 is bogus. > > > > > > > Xiaowei, can you comment? > > > > York _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
