Date:	Fri, 5 Feb 2016 08:29:48 -0600
From:	Bjorn Helgaas <helgaas@...nel.org>
To:	Олег Мороз <oleg.moroz@....vniiem.ru>
Cc:	linux-kernel@...r.kernel.org, Bjorn Helgaas <bhelgaas@...gle.com>,
	Jiang Liu <jiang.liu@...ux.intel.com>,
	linux-pci@...r.kernel.org
Subject: Re: PCI device driver broken between 4.2 and 4.3

On Tue, Feb 02, 2016 at 07:17:02PM +0300, Олег Мороз wrote:
> Ohhh. It's not my driver from scratch. I'm just trying to maintain
> it in working state.
> Could you please advice me some correct and small and simple (I know
> I ask a lot) PCI driver as example. Maybe it will be not so hard to
> fix this 1553b driver.

The best thing is to get that driver included in the Linux kernel
source.  Then we can avoid a lot of problems because we will update it
to match kernel updates, and when problems do occur, they're a lot
easier to debug and fix.

This book: https://lwn.net/Kernel/LDD3/ contains examples.

drivers/nvme/host/pci.c is a relatively new, clean driver, but
probably not very simple.

> 02.02.2016 19:13, Bjorn Helgaas пишет:
> >On Tue, Feb 02, 2016 at 08:04:39AM +0300, Олег Мороз wrote:
> >>it looks much better with pci=routeirq
> >>
> >>[  100.896723] *Before pci_enable_device IRQ 20*
> >>[  100.896735] *After pci_enable_device IRQ 20*
> >>[  100.896745] *Before pci_enable_device IRQ 21*
> >>[  100.896752] *After pci_enable_device IRQ 21*
> >If pci=routeirq makes a difference, it usually means your driver is
> >looking at dev->irq before it calls pci_enable_device().  I looked at
> >what I think is your driver
> >(https://github.com/qmor/elcus-1553-driver-linux/blob/master/driver/tmk1553.c),
> >but I didn't *see* that problem.  It does use a highly unconventional
> >strategy of calling pci_get_device() to locate devices, instead of
> >using pci_register_driver() like normal drivers do.
> >
> >You should not have to use pci=routeirq, and I've even considered
> >removing the option.
> >
> >>On Monday 01 of February 2016 15:08:23 Bjorn Helgaas wrote:
> >>>[+cc Yinghai]
> >>>
> >>>On Mon, Feb 01, 2016 at 08:18:35AM +0300, Олег Мороз wrote:
> >>>>Okay. I've started from driver level printk
> >>>>results are:
> >>>>
> >>>>On 4.2
> >>>>
> >>>>[414006.575989] Before pci_enable_device IRQ 20
> >>>>
> >>>>[414006.575991] After pci_enable_device IRQ 20
> >>>>
> >>>>[414006.575997] Before pci_enable_device IRQ 21
> >>>>
> >>>>[414006.575999] After pci_enable_device IRQ 21
> >>>>
> >>>>on 4.3
> >>>>
> >>>>[  114.862289] Before pci_enable_device IRQ 5
> >>>>
> >>>>[  114.862303] After pci_enable_device IRQ 5
> >>>>
> >>>>[  114.862316] Before pci_enable_device IRQ 5
> >>>>
> >>>>[  114.862326] After pci_enable_device IRQ 5
> >>>>
> >>>>I've got two cards, because of that pci_enable_device() calls twice.
> >>>Did you try booting with pci=routeirq as Yinghai suggested?  That's
> >>>not a fix, but if it does make things work, it may give us an idea for
> >>>how to fix it correctly.
> >>>
> >>>>On Friday 29 of January 2016 10:31:59 Bjorn Helgaas wrote:
> >>>>>On Thu, Jan 28, 2016 at 10:28:14PM +0300, Мороз Олег wrote:
> >>>>>>What i need to print out at first order?
> >>>>>Jiang, can you chime in here?
> >>>>>
> >>>>>991de2e59090 is related to IRQs, so I'd start by printing dev->irq in
> >>>>>your
> >>>>>driver before and after you call pci_enable_device().  Add some printks
> >>>>>in
> >>>>>pcibios_alloc_irq() and pcibios_enable_device() just to confirm that we
> >>>>>got
> >>>>>
> >>>>>there and when, e.g., add lines like this:
> >>>>>   dev_info(&dev->dev, "%s\n", __func__);
> >>>>>
> >>>>>Bjorn
> >>>>>
> >>>>>>27 янв. 2016 г. 16:22 пользователь Bjorn Helgaas <helgaas@...nel.org>
> >>>>написал:
> >>>>>>>On Wed, Jan 27, 2016 at 12:38:06PM +0300, Мороз Олег wrote:
> >>>>>>>>Also, my drive has no
> >>>>>>>>
> >>>>>>>>pcibios_enable_device()
> >>>>>>>>pcibios_alloc_irq()
> >>>>>>>>
> >>>>>>>>calls.
> >>>>>>>Those are internal interfaces used by the PCI core.  Drivers
> >>>>>>>shouldn't
> >>>>>>>call them directly.  Drivers normally call pci_enable_device(), and
> >>>>>>>those internal interfaces are used in that path.
> >>>>>>>
> >>>>>>>>26.01.2016 22:05, Олег Мороз пишет:
> >>>>>>>>>I confirmed it works in
> >>>>>>>>>
> >>>>>>>>>890e4847587f
> >>>>>>>>>
> >>>>>>>>>and do not works in
> >>>>>>>>>
> >>>>>>>>>991de2e59090
> >>>>>>>>>
> >>>>>>>>>26.01.2016 18:32, Bjorn Helgaas пишет:
> >>>>>>>>>>[+cc Jiang]
> >>>>>>>>>>
> >>>>>>>>>>On Mon, Jan 25, 2016 at 03:52:51PM -0600, Bjorn Helgaas wrote:
> >>>>>>>>>>>Hi Олег,
> >>>>>>>>>>>
> >>>>>>>>>>>On Sun, Jan 24, 2016 at 04:50:08PM +0300, Олег Мороз wrote:
> >>>>>>>>>>>>Okay. I've sent logs (dmesg and lspci) from both 4.2 and 4.3
> >>>>>>>>>>>>to bugzilla
> >>>>>>>>>>>I don't see anything wrong in either log.  Both v4.2 and v4.3
> >>>>>>>>>>>enumerate the device the same way, and the driver seems to
> >>>>>>>>>>>claim it
> >>>>>>>>>>>
> >>>>>>>>>>>the same way:
> >>>>>>>>>>>   pci 0000:0d:00.0: [10b5:9030] type 00 class 0x078000
> >>>>>>>>>>>   pci 0000:0d:00.0: reg 0x14: [io  0x2100-0x217f]
> >>>>>>>>>>>   pci 0000:0d:00.0: reg 0x18: [io  0x2380-0x239f]
> >>>>>>>>>>>   pci 0000:0d:00.0: PME# supported from D0 D3hot
> >>>>>>>>>>>   pci 0000:0d:01.0: [10b5:9030] type 00 class 0x078000
> >>>>>>>>>>>   pci 0000:0d:01.0: reg 0x14: [io  0x2180-0x21ff]
> >>>>>>>>>>>   pci 0000:0d:01.0: reg 0x18: [io  0x23a0-0x23bf]
> >>>>>>>>>>>   pci 0000:0d:01.0: PME# supported from D0 D3hot
> >>>>>>>>>>>   pci 0000:0d:02.0: [10b5:9030] type 00 class 0x078000
> >>>>>>>>>>>   pci 0000:0d:02.0: reg 0x14: [io  0x2200-0x227f]
> >>>>>>>>>>>   pci 0000:0d:02.0: reg 0x18: [io  0x2280-0x22ff]
> >>>>>>>>>>>   pci 0000:0d:02.0: reg 0x1c: [io  0x2300-0x237f]
> >>>>>>>>>>>   pci 0000:0d:02.0: PME# supported from D0 D3hot
> >>>>>>>>>>>   sja1000_plx_pci 0000:0d:02.0: Detected "Eclus CAN-200-PCI"
> >>>>>>>>>>>
> >>>>>>>>>>>card at slot #2
> >>>>>>>>>>>
> >>>>>>>>>>>   sja1000_plx_pci 0000:0d:02.0: Channel #1 at
> >>>>>>>>>>>
> >>>>>>>>>>>0x0000000000012280, irq 22 registered as can0
> >>>>>>>>>>>
> >>>>>>>>>>>   sja1000_plx_pci 0000:0d:02.0: Channel #2 at
> >>>>>>>>>>>
> >>>>>>>>>>>0x0000000000012300, irq 22 registered as can1
> >>>>>>>>>>>
> >>>>>>>>>>>   sja1000_plx_pci 0000:0d:02.0 can0: setting BTR0=0x03
> >>>>>>>>>>>   BTR1=0x37
> >>>>>>>>>>>
> >>>>>>>>>>>One option is always to bisect between v4.2 and v4.3 to see
> >>>>>>>>>>>which
> >>>>>>>>>>>commit made it stop working.  See
> >>>>>>>>>>>https://git-scm.com/docs/git-bisect
> >>>>>>>>>>Jiang, Олег bisected this to 991de2e59090 ("PCI, x86: Implement
> >>>>>>>>>>pcibios_alloc_irq() and pcibios_free_irq()").
> >>>>>>>>>>
> >>>>>>>>>>Олег, please double-check and confirm that 890e4847587f works
> >>>>>>>>>>and
> >>>>>>>>>>991de2e59090 fails.
> >>>>>>>>>>
> >>>>>>>>>>Then please add some printks in the pcibios_enable_device() and
> >>>>>>>>>>pcibios_alloc_irq() paths and in your driver to see exactly what
> >>>>>>>>>>changed
> >>>>>>>>>>between 890e4847587f and 991de2e59090
> >>>>>>>>>>
> >>>>>>>>>>Bjorn
> >>>>>>>>>>
> >>>>>>>>>>>>23.01.2016 17:54, Bjorn Helgaas пишет:
> >>>>>>>>>>>>>[+cc linux-kernel]
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Hi Олег,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>On Sat, Jan 23, 2016 at 1:08 AM, Олег Мороз
> >>>>>>>>>>>>>
> >>>>>>>>>>>>><oleg.moroz@....vniiem.ru> wrote:
> >>>>>>>>>>>>>>Hello. I've got a device driver for MIL-1553b card
> >>>>>>>>>>>>>>called TA1-PCI, which
> >>>>>>>>>>>>>>could be found at
> >>>>>>>>>>>>>>https://github.com/qmor/elcus-1553-driver-linux
> >>>>>>>>>>>>>>Card is using PLX_PCI9030 PCI controller.
> >>>>>>>>>>>>>>Today i've found that this driver compiles, installes,
> >>>>>>>>>>>>>>but is not working as
> >>>>>>>>>>>>>>it should.
> >>>>>>>>>>>>>>Looks like it not receives any interrupts from PCI. I've
> >>>>>>>>>>>>>>test it again with
> >>>>>>>>>>>>>>kernel
> >>>>>>>>>>>>>>4.2 and it works okay. What changes was made in PCI
> >>>>>>>>>>>>>>subsystem from 4.2 to
> >>>>>>>>>>>>>>4.3
> >>>>>>>>>>>>>>which could have impact this driver work.
> >>>>>>>>>>>>>Thank you very much for this problem report.  There were many
> >>>>>>>>>>>>>PCI
> >>>>>>>>>>>>>changes between v4.2 and v4.3, and without more information,
> >>>>>>>>>>>>>I
> >>>>>>>>>>>>>can't
> >>>>>>>>>>>>>guess what might be causing this problem.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>I opened a bug report at
> >>>>>>>>>>>>>https://bugzilla.kernel.org/show_bug.cgi?id=111211
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Please attach complete dmesg logs for both v4.2 and v4.3 to
> >>>>>>>>>>>>>that
> >>>>>>>>>>>>>bug
> >>>>>>>>>>>>>report.  Also, please attach the complete "lspci -vv" output
> >>>>>>>>>>>>>(as
> >>>>>>>>>>>>>root).
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Thanks!
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>Bjorn
> >>>>--
> >>>>To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> >>>>the body of a message to majordomo@...r.kernel.org
> >>>>More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>-- 
> >>С уважением,
> >>Олег Мороз
> >>Заместитель начальника отдела разработки ПО БВС КА
> >>--
> >>To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> >>the body of a message to majordomo@...r.kernel.org
> >>More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
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