On 18-12-2014 17:28, Prashant Sreedharan wrote: > On Thu, 2014-12-18 at 12:15 -0700, Bjorn Helgaas wrote: >> On Tue, Dec 16, 2014 at 12:54 PM, Michael Chan <mchan@xxxxxxxxxxxx> wrote: >>> On Tue, 2014-12-16 at 15:59 -0200, Marcelo Ricardo Leitner wrote: >>>> It's a >>>> 02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5722 >>>> Gigabit Ethernet PCI Express >>>> over here >>>> >>>> I put a WARN_ON(1) after those printks, and this is what I got: >>>> >>>> [ 1.550640] pci 0000:02:00.0: 1st 1 1 >>>> [ 1.550643] pci 0000:02:00.0: crs_timeout: 0 >>>> [ 1.550645] ------------[ cut here ]------------ >>>> [ 1.550651] WARNING: CPU: 6 PID: 364 at drivers/pci/probe.c:1445 pci_bus_read_dev_vendor_id+0x1d4/0x1e0() >>>> [ 1.550652] Modules linked in: i915(+) raid0 i2c_algo_bit drm_kms_helper drm e1000e(+) tg3(+) ptp pps_core video >>>> [ 1.550660] CPU: 6 PID: 364 Comm: systemd-udevd Not tainted 3.18.0-rc6+ #8 >>>> [ 1.550661] Hardware name: Dell Inc. OptiPlex 9010/03K80F, BIOS A15 08/12/2013 >>>> [ 1.550662] 0000000000000000 000000004de2d8dc ffff8807eabdf948 ffffffff8173db46 >>>> [ 1.550665] 0000000000000000 0000000000000000 ffff8807eabdf988 ffffffff81094d41 >>>> [ 1.550667] ffff8807eabdf968 ffff8807f1e27000 0000000000000000 0000000000000000 >>>> [ 1.550669] Call Trace: >>>> [ 1.550675] [<ffffffff8173db46>] dump_stack+0x46/0x58 >>>> [ 1.550679] [<ffffffff81094d41>] warn_slowpath_common+0x81/0xa0 >>>> [ 1.550681] [<ffffffff81094e5a>] warn_slowpath_null+0x1a/0x20 >>>> [ 1.550683] [<ffffffff813b2864>] pci_bus_read_dev_vendor_id+0x1d4/0x1e0 >>>> [ 1.550687] [<ffffffff813b7c3e>] pci_device_is_present+0x2e/0x50 >>>> [ 1.550693] [<ffffffffa003364f>] tg3_chip_reset+0x2f/0x940 [tg3] >>>> [ 1.550697] [<ffffffffa0033f9f>] tg3_halt+0x3f/0x1e0 [tg3] >>>> [ 1.550701] [<ffffffffa0044f83>] tg3_init_one+0xb83/0x1a40 [tg3] >>> >>> So does it work if you use a non-zero crs_timeout? The driver has >>> called tg3_halt() which may affect configuration read responses. I need >>> to check with the hardware team to see if the 5722 will return CRS in >>> this scenario. >> >> Any updates from the hardware team? >> >> This is a pretty serious regression, but as far as I can tell, it is >> not a PCI bug. The device should respond to a config read of vendor >> ID. If the driver does something that make the read return CRS >> status, I think the driver is responsible for doing whatever delay or >> other fixup is required. >> >> I'm inclined to reassign this bug to the tg3 driver unless you think >> the PCI core is doing something wrong here. >> >> Bjorn > > We were not able to reproduce this issue, could you please check what is > the value of reg 0x70, before the pci_device_is_present call is made ? > if bit 15 is set config access will be retried. > > --- a/drivers/net/ethernet/broadcom/tg3.c > +++ b/drivers/net/ethernet/broadcom/tg3.c > @@ -9025,6 +9025,7 @@ static int tg3_chip_reset(struct tg3 *tp) > void (*write_op)(struct tg3 *, u32, u32); > int i, err; > > + printk(KERN_ERR "config state: %x\n", tr32(TG3PCI_PCISTATE)); > if (!pci_device_is_present(tp->pdev)) > return -ENODEV; > With that PCI patch applied and my debugs, without the timeout hack (so crs_timeout=0): [ 1.545554] config state: 12b2 [ 1.548636] pci 0000:02:00.0: 1st 1 1 [ 1.548637] pci 0000:02:00.0: crs_timeout: 0 [ 1.548783] tg3 0000:02:00.0 eth0: Tigon3 [partno(BCM95722) rev a200] (PCI Express) MAC address 00:0a:f7:2b:9b:39 [ 1.548785] tg3 0000:02:00.0 eth0: attached PHY is 5722/5756 (10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[0]) [ 1.548786] tg3 0000:02:00.0 eth0: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[0] TSOcap[1] [ 1.548787] tg3 0000:02:00.0 eth0: dma_rwctrl[76180000] dma_mask[64-bit] [ 1.554389] tg3 0000:02:00.0 p1p1: renamed from eth0 ... That's the only time your printk got printed. Marcelo -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
