This is a note to let you know that I've just added the patch titled PCI: aardvark: Fix support for PCI_BRIDGE_CTL_BUS_RESET on emulated bridge to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pci-aardvark-fix-support-for-pci_bridge_ctl_bus_reset-on-emulated-bridge.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bc4fac42e5f8460af09c0a7f2f1915be09e20c71 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@xxxxxxxxxx> Date: Thu, 28 Oct 2021 20:56:58 +0200 Subject: PCI: aardvark: Fix support for PCI_BRIDGE_CTL_BUS_RESET on emulated bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pali Rohár <pali@xxxxxxxxxx> commit bc4fac42e5f8460af09c0a7f2f1915be09e20c71 upstream. Aardvark supports PCIe Hot Reset via PCIE_CORE_CTRL1_REG. Use it for implementing PCI_BRIDGE_CTL_BUS_RESET bit of PCI_BRIDGE_CONTROL register on emulated bridge. With this, the function pci_reset_secondary_bus() starts working and can reset connected PCIe card. Custom userspace script [1] which uses setpci can trigger PCIe Hot Reset and reset the card manually. [1] https://alexforencich.com/wiki/en/pcie/hot-reset-linux Link: https://lore.kernel.org/r/20211028185659.20329-7-kabel@xxxxxxxxxx Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> Signed-off-by: Marek Behún <kabel@xxxxxxxxxx> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/controller/pci-aardvark.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -793,6 +793,22 @@ advk_pci_bridge_emul_base_conf_read(stru *value = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); return PCI_BRIDGE_EMUL_HANDLED; + case PCI_INTERRUPT_LINE: { + /* + * From the whole 32bit register we support reading from HW only + * one bit: PCI_BRIDGE_CTL_BUS_RESET. + * Other bits are retrieved only from emulated config buffer. + */ + __le32 *cfgspace = (__le32 *)&bridge->conf; + u32 val = le32_to_cpu(cfgspace[PCI_INTERRUPT_LINE / 4]); + if (advk_readl(pcie, PCIE_CORE_CTRL1_REG) & HOT_RESET_GEN) + val |= PCI_BRIDGE_CTL_BUS_RESET << 16; + else + val &= ~(PCI_BRIDGE_CTL_BUS_RESET << 16); + *value = val; + return PCI_BRIDGE_EMUL_HANDLED; + } + default: return PCI_BRIDGE_EMUL_NOT_HANDLED; } @@ -809,6 +825,17 @@ advk_pci_bridge_emul_base_conf_write(str advk_writel(pcie, new, PCIE_CORE_CMD_STATUS_REG); break; + case PCI_INTERRUPT_LINE: + if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) { + u32 val = advk_readl(pcie, PCIE_CORE_CTRL1_REG); + if (new & (PCI_BRIDGE_CTL_BUS_RESET << 16)) + val |= HOT_RESET_GEN; + else + val &= ~HOT_RESET_GEN; + advk_writel(pcie, val, PCIE_CORE_CTRL1_REG); + } + break; + default: break; } Patches currently in stable-queue which might be from pali@xxxxxxxxxx are queue-5.14/pci-aardvark-fix-reporting-data-link-layer-link-active.patch queue-5.14/pci-aardvark-fix-configuring-reference-clock.patch queue-5.14/pci-aardvark-fix-support-for-bus-mastering-and-pci_command-on-emulated-bridge.patch queue-5.14/pci-mark-atheros-qca6174-to-avoid-bus-reset.patch queue-5.14/serial-core-fix-initializing-and-restoring-termios-speed.patch queue-5.14/pci-pci-bridge-emul-fix-emulation-of-w1c-bits.patch queue-5.14/pci-aardvark-fix-support-for-pci_bridge_ctl_bus_reset-on-emulated-bridge.patch queue-5.14/pci-aardvark-fix-checking-for-link-up-via-ltssm-state.patch queue-5.14/pci-aardvark-fix-return-value-of-msi-domain-.alloc-method.patch queue-5.14/pci-aardvark-read-all-16-bits-from-pcie_msi_payload_reg.patch queue-5.14/pci-aardvark-do-not-unmask-unused-interrupts.patch queue-5.14/pci-aardvark-do-not-clear-status-bits-of-masked-interrupts.patch queue-5.14/pci-aardvark-set-pci-bridge-class-code-to-pci-bridge.patch queue-5.14/pci-aardvark-fix-support-for-pci_rom_address1-on-emulated-bridge.patch