RE: [EXT] Re: [”PATCH” 2/5] PCI: armada8k: Add link-down handle

[Ben Peled]

Hi Jonathan,


> > In PCIE ISR routine caused by RST_LINK_DOWN we schedule work to handle
> > the link-down procedure.
> > Link-down procedure will:
> > 1. Remove PCIe bus
> > 2. Reset the MAC
> > 3. Reconfigure link back up
> > 4. Rescan PCIe bus
> >
> > Signed-off-by: Ben Peled <bpeled at marvell.com>
> 
> Trivial comment inline.
> 
> Also, something odd with quotes around PATCH in the title you probably
> want to clean up.
> 

I'll change the comment to more informative comments

> > ---
> >  drivers/pci/controller/dwc/pcie-armada8k.c | 68 ++++++++++++++++++++
> >  1 file changed, 68 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-armada8k.c
> > b/drivers/pci/controller/dwc/pcie-armada8k.c
> > index b2278b1..4eb8607 100644
> > --- a/drivers/pci/controller/dwc/pcie-armada8k.c
> > +++ b/drivers/pci/controller/dwc/pcie-armada8k.c
> > @@ -22,6 +22,8 @@
> >  #include <linux/resource.h>
> >  #include <linux/of_pci.h>
> >  #include <linux/of_irq.h>
> > +#include <linux/mfd/syscon.h>
> > +#include <linux/regmap.h>
> >
> >  #include "pcie-designware.h"
> >
> > @@ -33,6 +35,9 @@ struct armada8k_pcie {
> >  	struct clk *clk_reg;
> >  	struct phy *phy[ARMADA8K_PCIE_MAX_LANES];
> >  	unsigned int phy_count;
> > +	struct regmap *sysctrl_base;
> > +	u32 mac_rest_bitmask;
> > +	struct work_struct recover_link_work;
> >  };
> >
> >  #define PCIE_VENDOR_REGS_OFFSET		0x8000
> > @@ -73,6 +78,8 @@ struct armada8k_pcie {
> >  #define AX_USER_DOMAIN_MASK		0x3
> >  #define AX_USER_DOMAIN_SHIFT		4
> >
> > +#define UNIT_SOFT_RESET_CONFIG_REG	0x268
> > +
> >  #define to_armada8k_pcie(x)	dev_get_drvdata((x)->dev)
> >
> >  static void armada8k_pcie_disable_phys(struct armada8k_pcie *pcie) @@
> > -224,6 +231,49 @@ static int armada8k_pcie_host_init(struct pcie_port
> > *pp)
> >
> >  	return 0;
> >  }
> > +static void armada8k_pcie_recover_link(struct work_struct *ws) {
> > +	struct armada8k_pcie *pcie = container_of(ws, struct
> armada8k_pcie, recover_link_work);
> > +	struct pcie_port *pp = &pcie->pci->pp;
> > +	struct pci_bus *bus = pp->bridge->bus;
> > +	struct pci_dev *root_port;
> > +	int ret;
> > +
> > +	root_port = pci_get_slot(bus, 0);
> > +	if (!root_port) {
> > +		dev_err(pcie->pci->dev, "failed to get root port\n");
> > +		return;
> > +	}
> > +	pci_lock_rescan_remove();
> > +	pci_stop_and_remove_bus_device(root_port);
> > +	/*
> > +	 * Sleep needed to make sure all pcie transactions and access
> > +	 * are flushed before resetting the mac
> > +	 */
> > +	msleep(100);
> > +
> > +	/* Reset mac */
> > +	regmap_update_bits_base(pcie->sysctrl_base,
> UNIT_SOFT_RESET_CONFIG_REG,
> > +				pcie->mac_rest_bitmask, 0, NULL, false, true);
> > +	udelay(1);
> > +	regmap_update_bits_base(pcie->sysctrl_base,
> UNIT_SOFT_RESET_CONFIG_REG,
> > +				pcie->mac_rest_bitmask, pcie-
> >mac_rest_bitmask,
> > +				NULL, false, true);
> > +	udelay(1);
> > +	ret = armada8k_pcie_host_init(pp);
> > +	if (ret) {
> > +		dev_err(pcie->pci->dev, "failed to initialize host: %d\n", ret);
> > +		pci_unlock_rescan_remove();
> > +		pci_dev_put(root_port);
> > +		return;
> > +	}
> > +
> > +	bus = NULL;
> > +	while ((bus = pci_find_next_bus(bus)) != NULL)
> > +		pci_rescan_bus(bus);
> > +	pci_unlock_rescan_remove();
> > +	pci_dev_put(root_port);
> > +}
> >
> >  static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)  {
> > @@ -262,6 +312,9 @@ static irqreturn_t armada8k_pcie_irq_handler(int
> irq, void *arg)
> >  		 * initiate a link retrain. If link retrains were
> >  		 * possible, that is.
> >  		 */
> > +		if (pcie->sysctrl_base && pcie->mac_rest_bitmask)
> > +			schedule_work(&pcie->recover_link_work);
> > +
> >  		dev_dbg(pci->dev, "%s: link went down\n", __func__);
> >  	}
> >
> > @@ -330,6 +383,8 @@ static int armada8k_pcie_probe(struct
> > platform_device *pdev)
> >
> >  	pcie->pci = pci;
> >
> > +	INIT_WORK(&pcie->recover_link_work,
> armada8k_pcie_recover_link);
> > +
> >  	pcie->clk = devm_clk_get(dev, NULL);
> >  	if (IS_ERR(pcie->clk))
> >  		return PTR_ERR(pcie->clk);
> > @@ -357,6 +412,19 @@ static int armada8k_pcie_probe(struct
> platform_device *pdev)
> >  		goto fail_clkreg;
> >  	}
> >
> > +	pcie->sysctrl_base = syscon_regmap_lookup_by_phandle(pdev-
> >dev.of_node,
> > +						       "marvell,system-
> controller");
> > +	if (IS_ERR(pcie->sysctrl_base)) {
> > +		dev_warn(dev, "failed to find marvell,system-controller\n");
> > +		pcie->sysctrl_base = 0x0;
> 
> = NULL; ?
> 
I will change this to NULL in v3
> > +	}
> > +
> > +	ret = of_property_read_u32(pdev->dev.of_node, "marvell,mac-reset-
> bit-mask",
> > +				   &pcie->mac_rest_bitmask);
> > +	if (ret < 0) {
> > +		dev_warn(dev, "couldn't find mac reset bit mask: %d\n", ret);
> > +		pcie->mac_rest_bitmask = 0x0;
> > +	}
> >  	ret = armada8k_pcie_setup_phys(pcie);
> >  	if (ret)
> >  		goto fail_clkreg;

Thanks,
Ben