Re: [PATCH v5 0/2] PCI: mediatek-gen3: Add 2-lanes mode support + clock
Bjorn Helgaas <[email protected]> Fri, 7 Aug 2026 10:20:59 -0500
| Newsgroups | org.infradead.lists.linux-mediatek,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.linux-pci |
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| Message-ID | <20260807152059.GA39821@bhelgaas> |
On Fri, Aug 07, 2026 at 11:24:09AM +0800, Chen-Yu Tsai wrote: > On Fri, Aug 7, 2026 at 12:53 AM Christian Marangi <[email protected]> wrote: > > This small series introduce support for 2-lanes mode for Airoha AN7581 > > Just a nitpick, but I would probably name this something else, like > "cross-controller lane-bonding mode" or "lane stealing"? PCIe already > has 2x lanes as a standard feature, so this naming is a bit confusing. > It's not like dual-LVDS display in which LVDS is only a single lane. I suggested the "2-lane" and "x2" terminology because I assumed the result is what the PCIe spec would describe as a "x2 Link" consisting of two Lanes. If that's not the case, maybe "cross-controller lane-bonding mode" or "lane stealing" would be more accurate, but I don't know what those mean, so if we use them I would also like to know what the result looks like in standard PCIe terms. > > SoC. This is needed for correctly functionality of Eagle WiFi Card > > normally attached to this SoC that require a 2-line PCIe card to > > correctly work (and give the proper performance) > > > > The first 2 patch address a limitation of the PCIe implementation > > where the PERSTOUT reset were indirectly asserted and deasserted > > all at the same time (for all the 3 PCIe card) with PCIe > > enable and disable. > > The 2 patch address this and introduce correct reset to control > > reset line for the relevant PCIe line. > > > > The last 2 patch add additional logic and support to assert > > and deassert the PERSTOUT and also apply the required configuration > > for 2-lanes mode. > > > > 2-lanes mode is implemented in DT by adding the required property > > and by defining the "num-lanes" to 2.