PCI: rcar: Add the initialization of PCIe link in resume_noirq()

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>

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index c8febb0..6a4e435 100644 (file)
--- 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 platform_device *pdev)
        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,