Re: [PATCH 01/22] Added some infrastructure to allow assigning PCI device IRQs at device enable time and removed pci_fixup_irqs as the other change obsolites it.

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Mon, Aug 11, 2014 at 11:16:50AM +0100, Matthew Minter wrote:
>It seems that by coincidence, my testing boxes did not have any
>devices which needed the PCI_INTERRUPT_PIN fixed up. Therefore I had
>not noticed the fact the fixed value was not used in the enable path.

ok

>
>I would assume that someone with a different setup would have had a
>problem there however so thank you for pointing out this bug. I have
>integrated your fix into version 2 of the patch set.

thanks

>
>Many thanks.
>
>On 8 August 2014 02:20, Wei Yang <weiyang@linux.vnet.ibm.com> wrote:
>> On Thu, Aug 07, 2014 at 12:35:41PM +0100, Matthew Minter wrote:
>>>Just to confirm, are you saying that:
>>>
>>>>+
>>>>+      pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
>>>>+      pdev_assign_irq(dev, hbrg->swizzle_irq, hbrg->map_irq);
>>>>+
>>>
>>>Should become:
>>>
>>>>+
>>>>+     pdev_assign_irq(dev, hbrg->swizzle_irq, hbrg->map_irq);
>>>>+     pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
>>>>+
>>>
>>>So that we read the config byte after running the assignment and fixup?
>>>
>>>I had not thought about the case where the fixup changes the
>>>PCI_INTERRUPT_PIN value.
>>>It looks to me like you are correct there and this should indeed be fixed.
>>>I can certainly swap those around for the next patch revision if that
>>>is what you are suggesting?
>>>
>>
>> Yes, pci_read_config_byte() should be called after pdev_assign_irq().
>>
>>>I will give that a quick test but it sounds like you are correct.
>>
>> I am willing to know the result, especially in the original one, what pin
>> value you retrieved from pci_dev.
>>
>>>
>>>Many thanks,
>>>Matthew
>>>
>>>On 7 August 2014 04:43, Wei Yang <weiyang@linux.vnet.ibm.com> wrote:
>>>> On Tue, Aug 05, 2014 at 05:11:02PM +0100, matthew_minter@xyratex.com wrote:
>>>>>From: matthew_minter <matthew_minter@xyratex.com>
>>>>>
>>>>>---
>>>>> drivers/pci/Makefile      | 15 ++-------------
>>>>> drivers/pci/host-bridge.c |  2 +-
>>>>> drivers/pci/pci.c         |  6 +++++-
>>>>> drivers/pci/pci.h         |  1 +
>>>>> drivers/pci/probe.c       | 12 ------------
>>>>> drivers/pci/setup-irq.c   | 25 +++++++++----------------
>>>>> include/linux/pci.h       |  8 ++++----
>>>>> 7 files changed, 22 insertions(+), 47 deletions(-)
>>>>>
>>>>>diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
>>>>>index e04fe2d..38c4cb0 100644
>>>>>--- a/drivers/pci/Makefile
>>>>>+++ b/drivers/pci/Makefile
>>>>>@@ -4,7 +4,8 @@
>>>>>
>>>>> obj-y         += access.o bus.o probe.o host-bridge.o remove.o pci.o \
>>>>>                       pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
>>>>>-                      irq.o vpd.o setup-bus.o vc.o
>>>>>+                      irq.o vpd.o setup-bus.o vc.o setup-irq.o
>>>>>+
>>>>> obj-$(CONFIG_PROC_FS) += proc.o
>>>>> obj-$(CONFIG_SYSFS) += slot.o
>>>>>
>>>>>@@ -31,18 +32,6 @@ obj-$(CONFIG_PCI_ATS) += ats.o
>>>>> obj-$(CONFIG_PCI_IOV) += iov.o
>>>>>
>>>>> #
>>>>>-# Some architectures use the generic PCI setup functions
>>>>>-#
>>>>>-obj-$(CONFIG_ALPHA) += setup-irq.o
>>>>>-obj-$(CONFIG_ARM) += setup-irq.o
>>>>>-obj-$(CONFIG_UNICORE32) += setup-irq.o
>>>>>-obj-$(CONFIG_SUPERH) += setup-irq.o
>>>>>-obj-$(CONFIG_MIPS) += setup-irq.o
>>>>>-obj-$(CONFIG_TILE) += setup-irq.o
>>>>>-obj-$(CONFIG_SPARC_LEON) += setup-irq.o
>>>>>-obj-$(CONFIG_M68K) += setup-irq.o
>>>>>-
>>>>>-#
>>>>> # ACPI Related PCI FW Functions
>>>>> # ACPI _DSM provided firmware instance and string name
>>>>> #
>>>>>diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
>>>>>index 0e5f3c9..8ed186f 100644
>>>>>--- a/drivers/pci/host-bridge.c
>>>>>+++ b/drivers/pci/host-bridge.c
>>>>>@@ -16,7 +16,7 @@ static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
>>>>>       return bus;
>>>>> }
>>>>>
>>>>>-static struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus)
>>>>>+struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus)
>>>>> {
>>>>>       struct pci_bus *root_bus = find_pci_root_bus(bus);
>>>>>
>>>>>diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>>>>>index 63a54a3..d51d076 100644
>>>>>--- a/drivers/pci/pci.c
>>>>>+++ b/drivers/pci/pci.c
>>>>>@@ -1197,10 +1197,15 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
>>>>>       int err;
>>>>>       u16 cmd;
>>>>>       u8 pin;
>>>>>+      struct pci_host_bridge *hbrg = find_pci_host_bridge(dev->bus);
>>>>>
>>>>>       err = pci_set_power_state(dev, PCI_D0);
>>>>>       if (err < 0 && err != -EIO)
>>>>>               return err;
>>>>>+
>>>>>+      pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
>>>>>+      pdev_assign_irq(dev, hbrg->swizzle_irq, hbrg->map_irq);
>>>>>+
>>>>>       err = pcibios_enable_device(dev, bars);
>>>>>       if (err < 0)
>>>>>               return err;
>>>>>@@ -1209,7 +1214,6 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
>>>>>       if (dev->msi_enabled || dev->msix_enabled)
>>>>>               return 0;
>>>>>
>>>>>-      pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
>>>>
>>>> Not sure why you move this up.
>>>>
>>>> Before your change, the call flow would be like this:
>>>>
>>>> | scan_bus
>>>> |   + pci_fixup_irqs
>>>> |      +    pci_dev->irq and PCI_INTERRUPT_PIN assigned with correct number
>>>> |
>>>> | pci_enable_device, called from driver
>>>> |   + do_pci_enable_device, read the pin from pci_dev
>>>>
>>>> As my understanding, this ensures the pin read from hardware is fixuped. While
>>>> after your change, the pci_fixup_irqs is removed and the pin will be assigned
>>>> in pdev_assign_irq() after you fix it properly.
>>>>
>>>> Do I missed something?
>>>>
>>>>>       if (pin) {
>>>>>               pci_read_config_word(dev, PCI_COMMAND, &cmd);
>>>>>               if (cmd & PCI_COMMAND_INTX_DISABLE)
>>>>
>>>> --
>>>> Richard Yang
>>>> Help you, Help me
>>>>
>>>
>>>--
>>>
>>>
>>>------------------------------
>>>For additional information including the registered office and the treatment of Xyratex confidential information please visit www.xyratex.com
>>>
>>>------------------------------
>>
>> --
>> Richard Yang
>> Help you, Help me
>>
>
>-- 
>
>
>------------------------------
>For additional information including the registered office and the treatment of Xyratex confidential information please visit www.xyratex.com
>
>------------------------------

-- 
Richard Yang
Help you, Help me