This is a note to let you know that I've just added the patch titled
PCI: dra7xx: Create functional dependency between PCIe and PHY
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: pci-dra7xx-create-functional-dependency-between-pcie-and-phy.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Wed Dec 6 18:04:41 CET 2017
From: Kishon Vijay Abraham I kishon@ti.com Date: Mon, 9 Oct 2017 14:33:37 +0530 Subject: PCI: dra7xx: Create functional dependency between PCIe and PHY
From: Kishon Vijay Abraham I kishon@ti.com
[ Upstream commit 7a4db656a6350f8dd46f711bdef3b0e9c6e3f4cb ]
PCI core access configuration space registers in resume_noirq callbacks. In the case of dra7xx, PIPE3 PHY connected to PCIe controller has to be enabled before accessing configuration space registers. Since PIPE3 PHY is enabled by only configuring control module registers, no aborts has been observed so far (though during noirq stage, interface clock of PIPE3 PHY is not enabled).
With new TRM updates, PIPE3 PHY has to be initialized (PIPE3 PHY registers has to be accessed) as well which requires the interface clock of PIPE3 PHY to be enabled. The interface clock of PIPE3 PHY is derived from OCP2SCP and hence PCIe PHY is modeled as a child of OCP2SCP. Since pm_runtime is not enabled during noirq stage, pm_runtime_get_sync done in phy_init doesn't enable OCP2SCP clocks resulting in abort when PIPE3 PHY registers are accessed.
Create a function dependency between PCIe and PHY here to make sure PCIe is suspended before PCIe PHY/OCP2SCP and resumed after PCIe PHY/OCP2SCP.
Suggested-by: Grygorii Strashko grygorii.strashko@ti.com Signed-off-by: Kishon Vijay Abraham I kishon@ti.com Signed-off-by: Sekhar Nori nsekhar@ti.com Acked-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/dwc/pci-dra7xx.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
--- a/drivers/pci/dwc/pci-dra7xx.c +++ b/drivers/pci/dwc/pci-dra7xx.c @@ -11,6 +11,7 @@ */
#include <linux/delay.h> +#include <linux/device.h> #include <linux/err.h> #include <linux/interrupt.h> #include <linux/irq.h> @@ -594,6 +595,7 @@ static int __init dra7xx_pcie_probe(stru int i; int phy_count; struct phy **phy; + struct device_link **link; void __iomem *base; struct resource *res; struct dw_pcie *pci; @@ -649,11 +651,21 @@ static int __init dra7xx_pcie_probe(stru if (!phy) return -ENOMEM;
+ link = devm_kzalloc(dev, sizeof(*link) * phy_count, GFP_KERNEL); + if (!link) + return -ENOMEM; + for (i = 0; i < phy_count; i++) { snprintf(name, sizeof(name), "pcie-phy%d", i); phy[i] = devm_phy_get(dev, name); if (IS_ERR(phy[i])) return PTR_ERR(phy[i]); + + link[i] = device_link_add(dev, &phy[i]->dev, DL_FLAG_STATELESS); + if (!link[i]) { + ret = -EINVAL; + goto err_link; + } }
dra7xx->base = base; @@ -732,6 +744,10 @@ err_get_sync: pm_runtime_disable(dev); dra7xx_pcie_disable_phy(dra7xx);
+err_link: + while (--i >= 0) + device_link_del(link[i]); + return ret; }
Patches currently in stable-queue which might be from kishon@ti.com are
queue-4.14/pci-dra7xx-create-functional-dependency-between-pcie-and-phy.patch