mirror of
https://github.com/Ysurac/openmptcprouter.git
synced 2025-03-09 15:40:20 +00:00
81 lines
3.2 KiB
Diff
81 lines
3.2 KiB
Diff
Subject: [PATCH v2] PCI: aardvark: Implement workaround for PCIe Completion Timeout
|
|
Date: Tue, 2 Aug 2022 14:38:16 +0200
|
|
Message-Id: <20220802123816.21817-1-pali@kernel.org>
|
|
X-Mailer: git-send-email 2.20.1
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
Precedence: bulk
|
|
List-ID: <linux-pci.vger.kernel.org>
|
|
X-Mailing-List: linux-pci@vger.kernel.org
|
|
|
|
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(+)
|
|
|
|
--- a/drivers/pci/controller/pci-aardvark.c
|
|
+++ b/drivers/pci/controller/pci-aardvark.c
|
|
@@ -212,6 +212,8 @@ enum {
|
|
};
|
|
|
|
#define VENDOR_ID_REG (LMI_BASE_ADDR + 0x44)
|
|
+#define DEBUG_MUX_CTRL_REG (LMI_BASE_ADDR + 0x208)
|
|
+#define DIS_ORD_CHK BIT(30)
|
|
|
|
/* PCIe core controller registers */
|
|
#define CTRL_CORE_BASE_ADDR 0x18000
|
|
@@ -560,6 +562,11 @@ static void advk_pcie_setup_hw(struct ad
|
|
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;
|
|
@@ -1661,6 +1668,9 @@ static irqreturn_t advk_pcie_irq_handler
|
|
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;
|