Re: [PATCH] pciehp: Disable/enable link during slot power off/on

From: Yinghai Lu
Date: Fri Jan 27 2012 - 12:39:23 EST


On 01/27/2012 09:26 AM, Jesse Barnes wrote:

> On Fri, 02 Dec 2011 15:10:08 -0800
> Yinghai Lu <yinghai.lu@xxxxxxxxxx> wrote:
>
>>
>> One system have repeater in system board to support gen2 hotplug.
>>
>> Found when EM is removed from some slots, /var/log/message will be full of
>> "card present/not present" warning.
>>
>> It turns out root complex still try to train the link to repeater because
>> repeater is not reset.
>>
>> This patch will disable link to make repeater could reset properly.
>> Also could kill AER during EM removal.
>>
>> Recently when testing hotplug on one system under development, found if boot
>> the system without EM, and later hotplug does not work with Linux.
>> But other OS is ok.
>> The root cause is that bios left link disabled when slot is empty,
>> and other OS is playing link disable bit in link ctrl during power on/off.
>>
>> So We could do the same thing to disable/enable link during power off/on.
>>
>> Signed-off-by: Yinghai Lu <yinghai.lu@xxxxxxxxxx>
>
> Ok I had to massage that commit message quite a bit, please let me know
> if it's still accurate.
>
> The 100ms delay still needs to be clarified; if it's really necessary
> maybe we could move the delays into a delayed work handler?


Please you check updated versions that i sent later.

it was changed to three patches... i sent those patchs 1/123

git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-hp

you can find other patches in

git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci2

and

git://git.kernel.org/pub/scm/linux/kernel/git/yinghai/linux-yinghai.git for-pci-busn-alloc

Thanks

Yinghai
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