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Date: Thu, 17 May 2012 21:51:30 -0700
From: Greg KH <gregkh@linuxfoundation.org>
To: Prarit Bhargava <prarit@redhat.com>
Cc: linux-pci@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH] pci, Add AER_panic sysfs file
Message-ID: <20120518045130.GA3281@kroah.com>
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On Thu, May 17, 2012 at 01:04:30PM -0400, Prarit Bhargava wrote:
> Consider the following case
> 
> 		[ RP ]
> 		  |
> 		  |
> 	+---------+-----------+
> 	|	  |	      |
>        [H1]      [H2]        [X1]
> 
> where RP is a PCIE Root Port, H1 and H2 are devices with drivers that support
> PCIE AER driver error handling (ie, they have pci_error_handlers defined in
> the driver), and X1 is a device with a driver that does not support PCIE
> AER driver error handling.
> 
> If the Root Port takes an error what currently happens is that the
> bus resets and H1 & H2 call their slot_reset functions.  X1 does nothing.
> 
> In some cases a user may not wish the system to continue because X1 is
> an unhardened driver.  In these cases, the system should not do a bus reset,
> but rather the system should panic to avoid any further possible data
> corruption.
> 
> This patch implements an AER_panic sysfs entry for each root port which
> a user can modify.  AER_panic = 1, means the system will panic on a
> PCIE error which would have normally resulted in a secondary bus reset.

If you add/modify/delete a sysfs file, you have to also have a
corrisponding patch to Documentation/ABI/ in order to keep things sane.
Please do that as part of this patch the next time you submit it.

thanks,

greg k-h