lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230619150408.8468-5-manivannan.sadhasivam@linaro.org>
Date:   Mon, 19 Jun 2023 20:34:03 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     lpieralisi@...nel.org, kw@...ux.com, bhelgaas@...gle.com
Cc:     robh@...nel.org, andersson@...nel.org, konrad.dybcio@...aro.org,
        linux-pci@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org, steev@...i.org,
        quic_srichara@...cinc.com,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Subject: [PATCH v4 4/9] PCI: qcom: Do not advertise hotplug capability for IPs v2.7.0 and v1.9.0

SoCs making use of Qcom PCIe controller IPs v2.7.0 and v1.9.0 do not
support hotplug functionality. But the hotplug capability bit is set by
default in the hardware. This causes the kernel PCI core to register
hotplug service for the controller and send hotplug commands to it. But
those commands will timeout generating messages as below during boot and
suspend/resume.

[    5.782159] pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago)
[    5.810161] pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2048 msec ago)
[    7.838162] pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x07c0 (issued 2020 msec ago)
[    7.870159] pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x07c0 (issued 2052 msec ago)

This not only spams the console output but also induces a delay of a
couple of seconds. To fix this issue, let's clear the HPC bit in
PCI_EXP_SLTCAP register as a part of the post init sequence to not
advertise the hotplug capability for the controller.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
---
 drivers/pci/controller/dwc/pcie-qcom.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
index 391a45d1e70a..8f448156eccc 100644
--- a/drivers/pci/controller/dwc/pcie-qcom.c
+++ b/drivers/pci/controller/dwc/pcie-qcom.c
@@ -270,6 +270,20 @@ static int qcom_pcie_start_link(struct dw_pcie *pci)
 	return 0;
 }
 
+static void qcom_pcie_clear_hpc(struct dw_pcie *pci)
+{
+	u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
+
+	dw_pcie_dbi_ro_wr_en(pci);
+
+	val = readl(pci->dbi_base + offset + PCI_EXP_SLTCAP);
+	val &= ~PCI_EXP_SLTCAP_HPC;
+	writel(val, pci->dbi_base + offset + PCI_EXP_SLTCAP);
+
+	dw_pcie_dbi_ro_wr_dis(pci);
+}
+
 static void qcom_pcie_2_1_0_ltssm_enable(struct qcom_pcie *pcie)
 {
 	u32 val;
@@ -966,6 +980,13 @@ static int qcom_pcie_init_2_7_0(struct qcom_pcie *pcie)
 	return ret;
 }
 
+static int qcom_pcie_post_init_2_7_0(struct qcom_pcie *pcie)
+{
+	qcom_pcie_clear_hpc(pcie->pci);
+
+	return 0;
+}
+
 static void qcom_pcie_deinit_2_7_0(struct qcom_pcie *pcie)
 {
 	struct qcom_pcie_resources_2_7_0 *res = &pcie->res.v2_7_0;
@@ -1272,6 +1293,7 @@ static const struct qcom_pcie_ops ops_2_3_3 = {
 static const struct qcom_pcie_ops ops_2_7_0 = {
 	.get_resources = qcom_pcie_get_resources_2_7_0,
 	.init = qcom_pcie_init_2_7_0,
+	.post_init = qcom_pcie_post_init_2_7_0,
 	.deinit = qcom_pcie_deinit_2_7_0,
 	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
 };
@@ -1280,6 +1302,7 @@ static const struct qcom_pcie_ops ops_2_7_0 = {
 static const struct qcom_pcie_ops ops_1_9_0 = {
 	.get_resources = qcom_pcie_get_resources_2_7_0,
 	.init = qcom_pcie_init_2_7_0,
+	.post_init = qcom_pcie_post_init_2_7_0,
 	.deinit = qcom_pcie_deinit_2_7_0,
 	.ltssm_enable = qcom_pcie_2_3_2_ltssm_enable,
 	.config_sid = qcom_pcie_config_sid_1_9_0,
-- 
2.25.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ