From: Chen Yuanquan-B41889 <B41889@freescale.com>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org, r61911@freescale.com
Subject: Re: [PATCH] powerpc/pci-hotplug: fix the rescanned pci device's dma_set_mask issue
Date: Mon, 26 Nov 2012 13:29:58 +0800 [thread overview]
Message-ID: <50B2FE56.4080605@freescale.com> (raw)
In-Reply-To: <455E76A9-ABB3-4FF6-A19E-612E43223C4A@kernel.crashing.org>
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 <B41889@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);
}
>> 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
>
>
>
next prev parent reply other threads:[~2012-11-26 5:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-23 4:29 [PATCH] powerpc/pci-hotplug: fix the rescanned pci device's dma_set_mask issue Yuanquan Chen
2012-11-25 12:41 ` Kumar Gala
2012-11-26 5:29 ` Chen Yuanquan-B41889 [this message]
2012-11-28 2:34 ` Chen Yuanquan-B41889
2012-11-28 17:34 ` Kumar Gala
2012-12-04 14:32 ` Kumar Gala
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