Linux-PCI Archive on lore.kernel.org
 help / color / Atom feed
From: "Z.q. Hou" <zhiqiang.hou@nxp.com>
To: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"bhelgaas@google.com" <bhelgaas@google.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"l.subrahmanya@mobiveil.co.in" <l.subrahmanya@mobiveil.co.in>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	Leo Li <leoyang.li@nxp.com>,
	"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will.deacon@arm.com" <will.deacon@arm.com>
Cc: Mingkai Hu <mingkai.hu@nxp.com>,
	"M.h. Lian" <minghuan.lian@nxp.com>,
	Xiaowei Bao <xiaowei.bao@nxp.com>,
	"Z.q. Hou" <zhiqiang.hou@nxp.com>
Subject: [PATCHv4 26/28] PCI: mobiveil: ls_pcie_g4: add Workaround for A-011451
Date: Mon, 11 Mar 2019 09:33:32 +0000
Message-ID: <20190311093130.7209-27-Zhiqiang.Hou@nxp.com> (raw)
In-Reply-To: <20190311093130.7209-1-Zhiqiang.Hou@nxp.com>

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

When LX2 PCIe controller is sending multiple split completions and
ACK latency expires indicating that ACK should be send at priority.
But because of large number of split completions and FC update DLLP,
the controller does not give priority to ACK transmission. This
results into ACK latency timer timeout error at the link partner and
the pending TLPs are replayed by the link partner again.

Workaround:
1. Reduce the ACK latency timeout value to a very small value.
2. Restrict the number of completions from the LX2 PCIe controller
   to 1, by changing the Max Read Request Size (MRRS) of link partner
   to the same value as Max Packet size (MPS).

This patch implemented part 1, the part 2 can be set by kernel parameter
'pci=pcie_bus_perf'

This ERRATA is only for LX2160A Rev1.0, and it will be fixed
in Rev2.0.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
V4:
 - no change

 .../pci/controller/mobiveil/pci-layerscape-gen4.c | 15 +++++++++++++++
 drivers/pci/controller/mobiveil/pcie-mobiveil.h   |  4 ++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c b/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
index d2c5dbbd5e3c..20ce146788ca 100644
--- a/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
+++ b/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
@@ -82,12 +82,27 @@ static bool ls_pcie_g4_is_bridge(struct ls_pcie_g4 *pcie)
 	return header_type == PCI_HEADER_TYPE_BRIDGE;
 }
 
+static void workaround_A011451(struct ls_pcie_g4 *pcie)
+{
+	struct mobiveil_pcie *mv_pci = pcie->pci;
+	u32 val;
+
+	/* Set ACK latency timeout */
+	val = csr_readl(mv_pci, GPEX_ACK_REPLAY_TO);
+	val &= ~(ACK_LAT_TO_VAL_MASK << ACK_LAT_TO_VAL_SHIFT);
+	val |= (4 << ACK_LAT_TO_VAL_SHIFT);
+	csr_writel(mv_pci, val, GPEX_ACK_REPLAY_TO);
+}
+
 static int ls_pcie_g4_host_init(struct mobiveil_pcie *pci)
 {
 	struct ls_pcie_g4 *pcie = to_ls_pcie_g4(pci);
 
 	pcie->rev = csr_readb(pci, PCI_REVISION_ID);
 
+	if (pcie->rev == REV_1_0)
+		workaround_A011451(pcie);
+
 	return 0;
 }
 
diff --git a/drivers/pci/controller/mobiveil/pcie-mobiveil.h b/drivers/pci/controller/mobiveil/pcie-mobiveil.h
index ab43de5e4b2b..f0e2e4ae09b5 100644
--- a/drivers/pci/controller/mobiveil/pcie-mobiveil.h
+++ b/drivers/pci/controller/mobiveil/pcie-mobiveil.h
@@ -85,6 +85,10 @@
 #define PAB_AXI_AMAP_PEX_WIN_H(win)	PAB_REG_ADDR(0x0bac, win)
 #define PAB_INTP_AXI_PIO_CLASS		0x474
 
+#define GPEX_ACK_REPLAY_TO		0x438
+#define  ACK_LAT_TO_VAL_MASK		0x1fff
+#define  ACK_LAT_TO_VAL_SHIFT		0
+
 #define PAB_PEX_AMAP_CTRL(win)		PAB_REG_ADDR(0x4ba0, win)
 #define  AMAP_CTRL_EN_SHIFT		0
 #define  AMAP_CTRL_TYPE_SHIFT		1
-- 
2.17.1


  parent reply index

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-11  9:29 [PATCHv4 00/28] PCI: refactor Mobiveil driver and add PCIe Gen4 driver for NXP Layerscape SoCs Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 01/28] PCI: mobiveil: uniform the register accessors Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 02/28] PCI: mobiveil: format the code without function change Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 03/28] PCI: mobiveil: correct the returned error number Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 04/28] PCI: mobiveil: remove flag MSI_FLAG_MULTI_PCI_MSI Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 05/28] PCI: mobiveil: correct PCI base address in MEM/IO outbound windows Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 06/28] PCI: mobiveil: replace the resource list iteration function Z.q. Hou
2019-03-11  9:30 ` [PATCHv4 07/28] PCI: mobiveil: use WIN_NUM_0 explicitly for CFG outbound window Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 08/28] PCI: mobiveil: use the 1st inbound window for MEM inbound transactions Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 09/28] PCI: mobiveil: correct inbound/outbound window setup routines Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 10/28] PCI: mobiveil: fix the INTx process error Z.q. Hou
2019-03-11 14:08   ` Bjorn Helgaas
2019-03-12  4:42     ` Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 11/28] PCI: mobiveil: only fix up the Class Code field Z.q. Hou
2019-03-11 14:14   ` Bjorn Helgaas
2019-03-12  9:17     ` Z.q. Hou
2019-03-13 10:59       ` Subrahmanya Lingappa
2019-03-11  9:31 ` [PATCHv4 12/28] PCI: mobiveil: move out the link up waiting from mobiveil_host_init Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 13/28] PCI: mobiveil: move irq chained handler setup out of DT parse Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 14/28] PCI: mobiveil: initialize Primary/Secondary/Subordinate bus number Z.q. Hou
2019-03-11  9:31 ` [PATCHv4 15/28] dt-bindings: pci: mobiveil: change gpio_slave and apb_csr to optional Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 16/28] PCI: mobiveil: refactor Mobiveil PCIe Host Bridge IP driver Z.q. Hou
2019-03-26 17:34   ` Lorenzo Pieralisi
2019-03-27  2:04     ` Z.q. Hou
2019-03-27 17:39       ` Lorenzo Pieralisi
2019-03-28  2:09         ` Z.q. Hou
2019-03-28 16:09           ` Lorenzo Pieralisi
2019-03-29  6:07             ` Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 17/28] PCI: mobiveil: fix the checking of valid device Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 18/28] PCI: mobiveil: add link up condition check Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 19/28] PCI: mobiveil: continue to initialize the host upon no PCIe link Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 20/28] PCI: mobiveil: disabled IB and OB windows set by bootloader Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 21/28] PCI: mobiveil: add Byte and Half-Word width register accessors Z.q. Hou
2019-03-11  9:32 ` [PATCHv4 22/28] PCI: mobiveil: make mobiveil_host_init can be used to re-init host Z.q. Hou
2019-03-11  9:33 ` [PATCHv4 23/28] dt-bindings: pci: Add NXP Layerscape SoCs PCIe Gen4 controller Z.q. Hou
2019-03-11 22:11   ` Rob Herring
2019-03-12  3:17     ` Z.q. Hou
2019-03-12  9:42   ` Z.q. Hou
2019-03-11  9:33 ` [PATCHv4 24/28] PCI: mobiveil: add PCIe Gen4 RC driver for NXP Layerscape SoCs Z.q. Hou
2019-03-11 14:01   ` Bjorn Helgaas
2019-03-12  4:40     ` Z.q. Hou
2019-03-11  9:33 ` [PATCHv4 25/28] PCI: mobiveil: ls_pcie_g4: add Workaround for A-011577 Z.q. Hou
2019-03-13 14:51   ` Z.q. Hou
2019-03-11  9:33 ` Z.q. Hou [this message]
2019-03-11 17:34   ` [PATCHv4 26/28] PCI: mobiveil: ls_pcie_g4: add Workaround for A-011451 Bjorn Helgaas
2019-03-12  9:34     ` Z.q. Hou
2019-03-12 13:34       ` Bjorn Helgaas
2019-03-13 14:49         ` Z.q. Hou
2019-03-13 14:51   ` Z.q. Hou
2019-03-11  9:33 ` [PATCHv4 27/28] arm64: dts: freescale: lx2160a: add pcie DT nodes Z.q. Hou
2019-03-11  9:33 ` [PATCHv4 28/28] arm64: defconfig: Enable CONFIG_PCI_LAYERSCAPE_GEN4 Z.q. Hou
2019-03-11 13:33 ` [PATCHv4 00/28] PCI: refactor Mobiveil driver and add PCIe Gen4 driver for NXP Layerscape SoCs Bjorn Helgaas
2019-03-12  4:18   ` Z.q. Hou
2019-03-26 17:37 ` Lorenzo Pieralisi
2019-03-27  2:11   ` Z.q. Hou

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190311093130.7209-27-Zhiqiang.Hou@nxp.com \
    --to=zhiqiang.hou@nxp.com \
    --cc=bhelgaas@google.com \
    --cc=catalin.marinas@arm.com \
    --cc=devicetree@vger.kernel.org \
    --cc=l.subrahmanya@mobiveil.co.in \
    --cc=leoyang.li@nxp.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=mark.rutland@arm.com \
    --cc=minghuan.lian@nxp.com \
    --cc=mingkai.hu@nxp.com \
    --cc=robh+dt@kernel.org \
    --cc=shawnguo@kernel.org \
    --cc=will.deacon@arm.com \
    --cc=xiaowei.bao@nxp.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PCI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pci/0 linux-pci/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pci linux-pci/ https://lore.kernel.org/linux-pci \
		linux-pci@vger.kernel.org
	public-inbox-index linux-pci

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pci


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git