Commit 375328fa authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/controller/cadence' 

- Wait for link retrain to complete when working around the J721E i2085
  erratum with Gen2 mode (Siddharth Vadapalli)

* pci/controller/cadence:
  PCI: cadence: Fix Gen2 Link Retraining process
parents 41370553 0e12f830

drivers/pci/controller/cadence/pcie-cadence-host.c

+27 −0
Original line number Diff line number Diff line
@@ -12,6 +12,8 @@ 


#include "pcie-cadence.h"



#define LINK_RETRAIN_TIMEOUT HZ



static u64 bar_max_size[] = {

	[RP_BAR0] = _ULL(128 * SZ_2G),

	[RP_BAR1] = SZ_2G,
@@ -77,6 +79,27 @@ static struct pci_ops cdns_pcie_host_ops = { 
	.write		= pci_generic_config_write,

};



static int cdns_pcie_host_training_complete(struct cdns_pcie *pcie)

{

	u32 pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET;

	unsigned long end_jiffies;

	u16 lnk_stat;



	/* Wait for link training to complete. Exit after timeout. */

	end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;

	do {

		lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA);

		if (!(lnk_stat & PCI_EXP_LNKSTA_LT))

			break;

		usleep_range(0, 1000);

	} while (time_before(jiffies, end_jiffies));



	if (!(lnk_stat & PCI_EXP_LNKSTA_LT))

		return 0;



	return -ETIMEDOUT;

}



static int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie)

{

	struct device *dev = pcie->dev;
@@ -118,6 +141,10 @@ static int cdns_pcie_retrain(struct cdns_pcie *pcie) 
		cdns_pcie_rp_writew(pcie, pcie_cap_off + PCI_EXP_LNKCTL,

				    lnk_ctl);



		ret = cdns_pcie_host_training_complete(pcie);

		if (ret)

			return ret;



		ret = cdns_pcie_host_wait_for_link(pcie);

	}

	return ret;