Messages in this thread | | | Date | Thu, 31 Aug 2023 13:31:16 +0800 | Subject | Re: [PATCH v2] pci: loongson: Workaround MIPS firmware MRRS settings | From | Jiaxun Yang <> |
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在 2023/8/29 20:26, Linux regression tracking (Thorsten Leemhuis) 写道: > Hi, Thorsten here, the Linux kernel's regression tracker. Top-posting > for once, to make this easily accessible to everyone. > > What's the status here? From my point it looks like this regression that > was ported six weeks ago is still not fixed -- and it seems nothing has > happened since three weeks now. But maybe I'm just missing something, > that's why I'm asking.
Hi Thorsten,
Thanks for reaching back, unfortunately there is no progress so far.
+ Huacai, what's your opinion here? I do think this fix is in best shape for now.
Thanks - Jiaxun
> > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > -- > Everything you wanna know about Linux kernel regression tracking: > https://linux-regtracking.leemhuis.info/about/#tldr > If I did something stupid, please tell me, as explained on that page. > > #regzbot poke > > On 08.08.23 09:38, Jiaxun Yang wrote: >> >> 在 2023/8/6 22:30, Huacai Chen 写道: >>> Hi, Jiaxun, >>> >>> On Sun, Aug 6, 2023 at 10:20 AM Jiaxun Yang <jiaxun.yang@flygoat.com> >>> wrote: >>>> >>>> 在 2023/7/25 14:10, Jiaxun Yang 写道: >>>>> This is a partial revert of commit 8b3517f88ff2 ("PCI: >>>>> loongson: Prevent LS7A MRRS increases") for MIPS based Loongson. >>>>> >>>>> There are many MIPS based Loongson systems in wild that >>>>> shipped with firmware which does not set maximum MRRS properly. >>>>> >>>>> Limiting MRRS to 256 for all as MIPS Loongson comes with higher >>>>> MRRS support is considered rare. >>>>> >>>>> Cc: stable@vger.kernel.org >>>>> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217680 >>>>> Fixes: 8b3517f88ff2 ("PCI: loongson: Prevent LS7A MRRS increases") >>>>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> >>>> Ping? >>>> I expect this patch to go through PCI fixes tree. >>> Can we do it like this by modifying the existing loongson_mrrs_quirk()? >> Hmm, I'm not sure this will work, since loongson_mrrs_quirk only run on >> bridges >> but the old quirk should run on every single device. >> >> Thanks >> Jiaxun >> >>> static void loongson_mrrs_quirk(struct pci_dev *pdev) >>> { >>> /* >>> * Some Loongson PCIe ports have h/w limitations of maximum read >>> * request size. They can't handle anything larger than this. So >>> * force this limit on any devices attached under these ports. >>> */ >>> struct pci_host_bridge *bridge = >>> pci_find_host_bridge(pdev->bus); >>> >>> #ifdef CONFIG_MIPS >>> set_pcie_ports_to_mrrs_256_to_emulate_the_firmware_behavior(); >>> #endif >>> >>> bridge->no_inc_mrrs = 1; >>> } >>> >>>> Thanks >>>> - Jiaxun >>>> >>>>> --- >>>>> v2: Rename quirk name to: loongson_old_mrrs_quirk >>>>> --- >>>>> drivers/pci/controller/pci-loongson.c | 38 >>>>> +++++++++++++++++++++++++++ >>>>> 1 file changed, 38 insertions(+) >>>>> >>>>> diff --git a/drivers/pci/controller/pci-loongson.c >>>>> b/drivers/pci/controller/pci-loongson.c >>>>> index fe0f732f6e43..d0f68b102d10 100644 >>>>> --- a/drivers/pci/controller/pci-loongson.c >>>>> +++ b/drivers/pci/controller/pci-loongson.c >>>>> @@ -108,6 +108,44 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON, >>>>> DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON, >>>>> DEV_LS7A_PCIE_PORT6, loongson_mrrs_quirk); >>>>> >>>>> +#ifdef CONFIG_MIPS >>>>> +static void loongson_old_mrrs_quirk(struct pci_dev *pdev) >>>>> +{ >>>>> + struct pci_bus *bus = pdev->bus; >>>>> + struct pci_dev *bridge; >>>>> + static const struct pci_device_id bridge_devids[] = { >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS2K_PCIE_PORT0) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT0) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT1) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT2) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT3) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT4) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT5) }, >>>>> + { PCI_VDEVICE(LOONGSON, DEV_LS7A_PCIE_PORT6) }, >>>>> + { 0, }, >>>>> + }; >>>>> + >>>>> + /* look for the matching bridge */ >>>>> + while (!pci_is_root_bus(bus)) { >>>>> + bridge = bus->self; >>>>> + bus = bus->parent; >>>>> + /* >>>>> + * There are still some wild MIPS Loongson firmware won't >>>>> + * set MRRS properly. Limiting MRRS to 256 as MIPS >>>>> Loongson >>>>> + * comes with higher MRRS support is considered rare. >>>>> + */ >>>>> + if (pci_match_id(bridge_devids, bridge)) { >>>>> + if (pcie_get_readrq(pdev) > 256) { >>>>> + pci_info(pdev, "limiting MRRS to 256\n"); >>>>> + pcie_set_readrq(pdev, 256); >>>>> + } >>>>> + break; >>>>> + } >>>>> + } >>>>> +} >>>>> +DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, >>>>> loongson_old_mrrs_quirk); >>>>> +#endif >>>>> + >>>>> static void loongson_pci_pin_quirk(struct pci_dev *pdev) >>>>> { >>>>> pdev->pin = 1 + (PCI_FUNC(pdev->devfn) & 3);
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