On Nov 27, 2012, at 8:34 PM, Chen Yuanquan-B41889 wrote:
> On 11/25/2012 08:41 PM, Kumar Gala wrote:
>> On Nov 22, 2012, at 10:29 PM, Yuanquan Chen wrote:
>>
>>> On powerpc arch, dma_ops of rescanned pci device after system's booting up
>>> won't be
>>> initialized by system, so it will fail to execute the dma_set_mask in the
>>> device's
>>> driver. Initialize it to solve this issue.
>>>
>>> Signed-off-by: Yuanquan Chen <b41...@freescale.com>
>>> ---
>>> arch/powerpc/include/asm/dma-mapping.h | 7 +++++--
>>> 1 file changed, 5 insertions(+), 2 deletions(-)
>> This is not the right way to get the dma_ops setup. You need to find some
>> other point for the hotplug scenario to get the dma_ops setup.
>>
>> - k
>
> Hi Kumar,
>
> I read the code about pci bus scan and rescan. Only the pcibios_fixup_bus in
> pci_scan_child_bus and
> pcibios_enable_device in pci_rescan_bus are arch related code. The
> pcibios_fixup_bus won't be called
> for the rescanned PCI devices due to the bus->is_added has been set for the
> first scanning at boot time.
> So I think it's more reasonable to do the same work as pcibios_fixup_bus for
> rescanned PCI device in
> pcibios_enable_device. The patch code is a copy of pcibios_setup_bus_devices
> called by pcibios_fixup_bus,
> It can solve the dma_set_mask and irq related issues of rescanned PCI device
> on powerpc arch. What's
> your opinion?
>
> Thanks,
> yuanquan
>
> diff --git a/arch/powerpc/kernel/pci-common.c
> b/arch/powerpc/kernel/pci-common.c
> index 7f94f76..30f7d61 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -1496,6 +1496,23 @@ int pcibios_enable_device(struct pci_dev *dev, int
> mask)
> if (ppc_md.pcibios_enable_device_hook(dev))
> return -EINVAL;
>
> + if (!dev->is_added) {
> + set_dev_node(&dev->dev, pcibus_to_node(dev->bus));
> +
> + /* Hook up default DMA ops */
> + set_dma_ops(&dev->dev, pci_dma_ops);
> + set_dma_offset(&dev->dev, PCI_DRAM_OFFSET);
> +
> + /* Additional platform DMA/iommu setup */
> + if (ppc_md.pci_dma_dev_setup)
> + ppc_md.pci_dma_dev_setup(dev);
> +
> + /* Read default IRQs and fixup if necessary */
> + pci_read_irq_line(dev);
> + if (ppc_md.pci_irq_fixup)
> + ppc_md.pci_irq_fixup(dev);
> + }
> +
> return pci_enable_resources(dev, mask);
> }
>
This looks better than the first patch.. I'm surprised that the IBM guys don't
run into a similar issue with their hotplug support.
Maybe Ben or someone else will comment.
- k
>>> diff --git a/arch/powerpc/include/asm/dma-mapping.h
>>> b/arch/powerpc/include/asm/dma-mapping.h
>>> index 7816087..22eae53 100644
>>> --- a/arch/powerpc/include/asm/dma-mapping.h
>>> +++ b/arch/powerpc/include/asm/dma-mapping.h
>>> @@ -126,8 +126,11 @@ static inline int dma_supported(struct device *dev,
>>> u64 mask)
>>> {
>>> struct dma_map_ops *dma_ops = get_dma_ops(dev);
>>>
>>> - if (unlikely(dma_ops == NULL))
>>> - return 0;
>>> + if (unlikely(dma_ops == NULL)) {
>>> + set_dma_ops(dev, &dma_direct_ops);
>>> + set_dma_offset(dev, PCI_DRAM_OFFSET);
>>> + dma_ops = &dma_direct_ops;
>>> + }
>>> if (dma_ops->dma_supported == NULL)
>>> return 1;
>>> return dma_ops->dma_supported(dev, mask);
>>> --
>>> 1.7.9.5
>>>
>>>
>>> _______________________________________________
>>> Linuxppc-dev mailing list
>>> Linuxppc-dev@lists.ozlabs.org
>>> https://lists.ozlabs.org/listinfo/linuxppc-dev
>>
>>
>>
>
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