Re: [PATCH 1/1] Fix PCIe LER when GRUB2 accesses non-enabled MMIO data from VGA

[Mike Travis]

On 3/29/2018 2:36 AM, Daniel Kiper wrote:
> On Thu, Mar 29, 2018 at 05:29:01PM +0800, Michael Chang wrote:
> > On Thu, Mar 29, 2018 at 11:02:51AM +0200, Daniel Kiper wrote:
> > > On Wed, Mar 28, 2018 at 11:42:18AM -0500, address@hidden wrote:
> > > > A GPU inserted into a PCIe I/O slot disappears during system startup.
> > > > The problem centers around GRUB and a specific VGA init function in
> > > > efi_uga.c.  This causes an LER (link error recorvery) because the MMIO
> > > > memory has not been enabled before attempting access.
> > > >
> > > > The fix is to add the same coding used in other VGA drivers, specifically
> > > > to add a check to insure that it is indeed a VGA controller.  And then
> > > > enable the MMIO address space with the specific bits.
> > > >
> > > > Signed-off-by: Mike Travis <address@hidden>
> > > > Reviewed-by: Michael Chang <address@hidden>
> > > > Reviewed-by: Daniel Kiper <address@hidden>
> > >
> > > Well, please do not add somebody RB tag if he/she did not explicitly
> > > asked you to do that. And even in that case I was not able to look at
> > > this patch in advance. So, my RB should not be here. Additionally, in
> > > this situation I would like to ask if Michael approved his RB?
> >
> > We did have discussion about the patch before it was submitted upstream but I
> > did not ask for RB as well.
> >
> > > Anyway, patch LGTM except one nitpick. I will apply the patch, in a week or
> > > so, with Michael's RB if I get confirmation that he approved it earlier.
> >
> > As I did not ask for it, it has to be removed.
>
> OK, I will commit this patch without your RB.
>
> Daniel

Sorry, I was not aware of this custom.  I thought that if someone 
reviewed the code then that was an indication that it should be noted. 
I am aware of the more restrictive Acked-by which is normally sent by 
the "acker" to the submitter.  I will be more mindful of this in the 
future.  (This is my first posting to any of the GNU mail lists).

Thanks,
Mike