+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
