Re: [PATCH] powerpc/pci: Improve device hotplug initialization

From: Chen Yuanquan-B41889
Date: Sun Jun 02 2013 - 22:29:08 EST

On 06/01/2013 09:58 PM, Guenter Roeck wrote:
On Fri, May 31, 2013 at 03:44:07PM +1000, Benjamin Herrenschmidt wrote:
On Thu, 2013-05-30 at 22:14 -0700, Guenter Roeck wrote:
On Wed, May 29, 2013 at 05:30:41PM +0800, Chen Yuanquan-B41889 wrote:
On 05/29/2013 01:35 AM, Guenter Roeck wrote:
bios_add_device(). Drop explicit calls to pcibios_setup_device();
this makes pcibios_setup_bus_devices() a noop function which could
Yeah, it's more reasonable to do the irq and DMA related initialization
in one code path for all devices.

Any comments / feedback on the code itself ?
Sorry, I haven't had a chance to review it yet, I'm fairly bogged down
at the moment. I want to tread carefully because the previous iteration
of changing that stuff did break a few platforms in the end.

Hi Ben,

the comment was actuially directed towards Yuanquan.

No problem, take your time. I did my best to test it, but I agree that this is a
critical area of the code, and it would be desirable to get additional scrutiny
and test feedback.

The code has been running in our system (P2020 and P5040) for several months.
I was preparing a patch for upstream submission when I noticed commit 37f02195b.
After testing ithis commit, I noticed the problems with it and wrote this patch,
which aligns the code with our initial patch. I tested it as good as I could on
our systems as well as with a P5040 evaluation board and an Intel GE PCIe


Hi Guenter,

Your patch makes sure the initialization of DMA and irq in one code path and also
avoids the initialization called two times(in pci bus scanning and pci_enable_device()
in device driver) for no-hot-plugged pci device. It's much more reasonable!

I don't know why you also remove the function "set_dev_node()" ? As I know, the
function just be called here. I think it should remain in your new function


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