mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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3ea8529acc
Currently the reset-gpio DT property which controls the PCI bus device reset signal defaults to active-low reset sequence (L=reset state, H=operation state) plus the code in reset function isn't GPIO polarity aware - it doesn't matter if the defined reset-gpio is active-low or active-high, it will always result into active-low reset sequence. I've tried to fix it properly and change the reset-gpio reset sequence to be polarity-aware, but this patch has been accepted and then reverted as it has introduced few backward incompatible issues: 1. Some DTBs, for example, imx6qdl-sabresd, don't define reset-gpio polarity correctly: reset-gpio = <&gpio7 12 0>; which means that it's defined as active-high, but in reality it's active-low; thus it wouldn't work without a DTS fix. 2. The logic in the reset function is inverted: gpio_set_value_cansleep(imx6_pcie->reset_gpio, 0) msleep(100); gpio_set_value_cansleep(imx6_pcie->reset_gpio, 1); so even if some of the i.MX6 boards had reset-gpio polarity defined correctly in their DTSes, they would stop working. As we can't break old DTBs, we can't fix them, so we need to introduce this new DT reset-gpio-active-high boolean property so we can support boards with active-high reset sequence. This active-high reset sequence is for example needed on Apalis SoMs, where GPIO1_IO28, used to PCIe reset is not connected directly to PERST# PCIe signal, but it's ORed with RESETBMCU coming off the PMIC, and thus is inverted, active-high. Tested-by: Tim Harvey <tharvey@gateworks.com> # Gateworks Ventana boards (which have active-low PERST#) Signed-off-by: Petr Štetiar <ynezz@true.cz> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Rob Herring <robh@kernel.org> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| pci-dra7xx.c | ||
| pci-exynos.c | ||
| pci-host-common.c | ||
| pci-host-common.h | ||
| pci-host-generic.c | ||
| pci-hyperv.c | ||
| pci-imx6.c | ||
| pci-keystone-dw.c | ||
| pci-keystone.c | ||
| pci-keystone.h | ||
| pci-layerscape.c | ||
| pci-mvebu.c | ||
| pci-rcar-gen2.c | ||
| pci-tegra.c | ||
| pci-thunder-ecam.c | ||
| pci-thunder-pem.c | ||
| pci-versatile.c | ||
| pci-xgene-msi.c | ||
| pci-xgene.c | ||
| pcie-altera-msi.c | ||
| pcie-altera.c | ||
| pcie-designware-plat.c | ||
| pcie-designware.c | ||
| pcie-designware.h | ||
| pcie-hisi.c | ||
| pcie-iproc-bcma.c | ||
| pcie-iproc-msi.c | ||
| pcie-iproc-platform.c | ||
| pcie-iproc.c | ||
| pcie-iproc.h | ||
| pcie-qcom.c | ||
| pcie-rcar.c | ||
| pcie-spear13xx.c | ||
| pcie-xilinx-nwl.c | ||
| pcie-xilinx.c | ||