Commit 82ba129b authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

powerpc/powernv: Handle PCI-X/PCIe reset delay

The firmware doesn't wait after lifting the PCI reset. However it does
timestamp it in the device tree. We use that to ensure we wait long
enough (3s is our current arbitrary setting) from that timestamp to
actually probing the bus.

Signed-off-by: default avatarBenjamin Herrenschmidt <>
parent c1a2562a
......@@ -35,6 +35,8 @@
#include "powernv.h"
#include "pci.h"
/* Delay in usec */
#define PCI_RESET_DELAY_US 3000000
#define cfg_dbg(fmt...) do { } while(0)
//#define cfg_dbg(fmt...) printk(fmt)
......@@ -354,6 +356,35 @@ static void __devinit pnv_pci_dma_dev_setup(struct pci_dev *pdev)
pnv_pci_dma_fallback_setup(hose, pdev);
static int pnv_pci_probe_mode(struct pci_bus *bus)
struct pci_controller *hose = pci_bus_to_host(bus);
const __be64 *tstamp;
u64 now, target;
/* We hijack this as a way to ensure we have waited long
* enough since the reset was lifted on the PCI bus
if (bus != hose->bus)
tstamp = of_get_property(hose->dn, "reset-clear-timestamp", NULL);
if (!tstamp || !*tstamp)
now = mftb() / tb_ticks_per_usec;
target = (be64_to_cpup(tstamp) / tb_ticks_per_usec)
pr_devel("pci %04d: Reset target: 0x%llx now: 0x%llx\n",
hose->global_number, target, now);
if (now < target)
msleep((target - now + 999) / 1000);
void __init pnv_pci_init(void)
struct device_node *np;
......@@ -384,6 +415,7 @@ void __init pnv_pci_init(void)
ppc_md.pci_dma_dev_setup = pnv_pci_dma_dev_setup;
ppc_md.tce_build = pnv_tce_build;
ppc_md.tce_free = pnv_tce_free;
ppc_md.pci_probe_mode = pnv_pci_probe_mode;
/* Configure MSIs */
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