diff options
Diffstat (limited to 'pkgs/patches-linux-5.15/100-aardvark-workaround-PCIe.patch')
| -rw-r--r-- | pkgs/patches-linux-5.15/100-aardvark-workaround-PCIe.patch | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/pkgs/patches-linux-5.15/100-aardvark-workaround-PCIe.patch b/pkgs/patches-linux-5.15/100-aardvark-workaround-PCIe.patch new file mode 100644 index 0000000..39a7934 --- /dev/null +++ b/pkgs/patches-linux-5.15/100-aardvark-workaround-PCIe.patch @@ -0,0 +1,81 @@ +From b004eff0818f657f66a6e1dc63aca0ffd9b1fb2f Mon Sep 17 00:00:00 2001 +From: Pali Rohár <pali@kernel.org> +Date: Wed, 31 Aug 2022 19:44:08 +0200 +Subject: [PATCH] PCI: aardvark: Implement workaround for PCIe Completion + Timeout + +Marvell Armada 3700 Functional Errata, Guidelines, and Restrictions +document describes in erratum 3.12 PCIe Completion Timeout (Ref #: 251), +that PCIe IP does not support a strong-ordered model for inbound posted vs. +outbound completion. + +As a workaround for this erratum, DIS_ORD_CHK flag in Debug Mux Control +register must be set. It disables the ordering check in the core between +Completions and Posted requests received from the link. + +Marvell also suggests to do full memory barrier at the beginning of +aardvark summary interrupt handler before calling interrupt handlers of +endpoint drivers in order to minimize the risk for the race condition +documented in the Erratum between the DMA done status reading and the +completion of writing to the host memory. + +More details about this issue and suggested workarounds are in discussion: +https://lore.kernel.org/linux-pci/BN9PR18MB425154FE5019DCAF2028A1D5DB8D9@BN9PR18MB4251.namprd18.prod.outlook.com/t/#u + +It was reported that enabling this workaround fixes instability issues and +"Unhandled fault" errors when using 60 GHz WiFi 802.11ad card with Qualcomm +QCA6335 chip under significant load which were caused by interrupt status +stuck in the outbound CMPLT queue traced back to this erratum. + +This workaround fixes also kernel panic triggered after some minutes of +usage 5 GHz WiFi 802.11ax card with Mediatek MT7915 chip: + + Internal error: synchronous external abort: 96000210 [#1] SMP + Kernel panic - not syncing: Fatal exception in interrupt + +Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> +Signed-off-by: Pali Rohár <pali@kernel.org> +Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") +Cc: stable@vger.kernel.org +--- + drivers/pci/controller/pci-aardvark.c | 10 ++++++++++ + 1 file changed, 10 insertions(+) + +diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c +index f3984bdf1d96..defaf74935a3 100644 +--- a/drivers/pci/controller/pci-aardvark.c ++++ b/drivers/pci/controller/pci-aardvark.c +@@ -215,6 +215,8 @@ enum { + }; + + #define VENDOR_ID_REG (LMI_BASE_ADDR + 0x44) ++#define DEBUG_MUX_CTRL_REG (LMI_BASE_ADDR + 0x208) ++#define DIS_ORD_CHK BIT(30) + #define PME_MSG_GEN_CTRL (LMI_BASE_ADDR + 0x220) + #define SEND_SET_SLOT_POWER_LIMIT BIT(13) + #define SEND_PME_TURN_OFF BIT(14) +@@ -611,6 +613,11 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) + PCIE_CORE_CTRL2_TD_ENABLE; + advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG); + ++ /* Disable ordering checks, workaround for erratum 3.12 "PCIe completion timeout" */ ++ reg = advk_readl(pcie, DEBUG_MUX_CTRL_REG); ++ reg |= DIS_ORD_CHK; ++ advk_writel(pcie, reg, DEBUG_MUX_CTRL_REG); ++ + /* Set lane X1 */ + reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG); + reg &= ~LANE_CNT_MSK; +@@ -1803,6 +1810,9 @@ static irqreturn_t advk_pcie_irq_handler(int irq, void *arg) + struct advk_pcie *pcie = arg; + u32 status; + ++ /* Full memory barrier (ARM dsb sy), workaround for erratum 3.12 "PCIe completion timeout" */ ++ mb(); ++ + status = advk_readl(pcie, HOST_CTRL_INT_STATUS_REG); + if (!(status & PCIE_IRQ_CORE_INT)) + return IRQ_NONE; +-- +2.34.1 + |