[PATCH 5.1 099/122] PCI: rcar: Add the initialization of PCIe link in resume_noirq()

Greg Kroah-Hartman
2019-05-23T19:30:57Z

From: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com>

commit be20bbcb0a8cb5597cc62b3e28d275919f3431df upstream.

Reestablish the PCIe link very early in the resume process in case it
went down to prevent PCI accesses from hanging the bus. Such accesses
can happen early in the PCI resume process, as early as the
SUSPEND_RESUME_NOIRQ step, thus the link must be reestablished in the
driver resume_noirq() callback.

Fixes: e015f88c368d ("PCI: rcar: Add support for R-Car H3 to pcie-rcar")
Signed-off-by: Kazufumi Ikeda <kaz-ikeda@xc.jp.nec.com>
Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
[lorenzo.pieralisi@arm.com: reformatted commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: stable@vger.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pci/controller/pcie-rcar.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -46,6 +46,7 @@

/* Transfer control */
#define PCIETCTLR 0x02000
+#define DL_DOWN BIT(3)
#define CFINIT 1
#define PCIETSTR 0x02004
#define DATA_LINK_ACTIVE 1
@@ -94,6 +95,7 @@
#define MACCTLR 0x011058
#define SPEED_CHANGE BIT(24)
#define SCRAMBLE_DISABLE BIT(27)
+#define PMSR 0x01105c
#define MACS2R 0x011078
#define MACCGSPSETR 0x011084
#define SPCNGRSN BIT(31)
@@ -1130,6 +1132,7 @@ static int rcar_pcie_probe(struct platfo
pcie = pci_host_bridge_priv(bridge);

pcie->dev = dev;
+ platform_set_drvdata(pdev, pcie);

err = pci_parse_request_of_pci_ranges(dev, &pcie->resources, NULL);
if (err)
@@ -1221,10 +1224,28 @@ err_free_bridge:
return err;
}

+static int rcar_pcie_resume_noirq(struct device *dev)
+{
+ struct rcar_pcie *pcie = dev_get_drvdata(dev);
+
+ if (rcar_pci_read_reg(pcie, PMSR) &&
+ !(rcar_pci_read_reg(pcie, PCIETCTLR) & DL_DOWN))
+ return 0;
+
+ /* Re-establish the PCIe link */
+ rcar_pci_write_reg(pcie, CFINIT, PCIETCTLR);
+ return rcar_pcie_wait_for_dl(pcie);
+}
+
+static const struct dev_pm_ops rcar_pcie_pm_ops = {
+ .resume_noirq = rcar_pcie_resume_noirq,
+};
+
static struct platform_driver rcar_pcie_driver = {
.driver = {
.name = "rcar-pcie",
.of_match_table = rcar_pcie_of_match,
+ .pm = &rcar_pcie_pm_ops,
.suppress_bind_attrs = true,
},
.probe = rcar_pcie_probe,