Re: FAILED: patch "[PATCH] igc: read before write to SRRCTL register" failed to apply to 6.1-stable tree

[florian@bezdeka.de]

Am 2023-05-11 08:56, schrieb Song, Yoong Siang:
> On Thursday, May 11, 2023 6:46 AM , Greg KH 
> <gregkh@linuxfoundation.org> wrote:
>> On Thu, May 11, 2023 at 12:01:36AM +0200, Florian Bezdeka wrote:
>>> Hi all,
>>> 
>>> On 07.05.23 08:44, gregkh@linuxfoundation.org wrote:
>>> >
>>> > The patch below does not apply to the 6.1-stable tree.
>>> > If someone wants it applied there, or to any other stable or
>>> > longterm tree, then please email the backport, including the
>>> > original git commit id to <stable@vger.kernel.org>.
>>> >
>>> > To reproduce the conflict and resubmit, you may use the following commands:
>>> >
>>> > git fetch
>>> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/
>>> > linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x
>>> > 3ce29c17dc847bf4245e16aad78a7617afa96297
>>> > # <resolve conflicts, build, test, etc.> git commit -s git
>>> > send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023050749-
>> deskwork-snowboard-82cf@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
>>> 
>>> Is someone already working on that? I would love to see this patch in
>>> 6.1. If no further activities are planned I might have the 
>>> option/time
>>> to supply a backport as well.
>> 
>> Please supply a backport, I don't think anyone is working on it :)
> 
> Hi Florian,
> 
> I not yet got plan to backport the patch, so I am more than happy
> if you could supply a backport.
> 
> Most probably the issue is due to missing "#include 
> <linux/bitfield.h>".

Exactly.

The build failure:

In file included from drivers/net/ethernet/intel/igc/igc_hw.h:17,
                  from drivers/net/ethernet/intel/igc/igc.h:17,
                  from drivers/net/ethernet/intel/igc/igc_main.c:19:
drivers/net/ethernet/intel/igc/igc_main.c: In function 
‘igc_configure_rx_ring’:
drivers/net/ethernet/intel/igc/igc_base.h:92:41: error: implicit 
declaration of function ‘FIELD_PREP’ 
[-Werror=implicit-function-declaration]
    92 | #define IGC_SRRCTL_BSIZEHDR(x)          
FIELD_PREP(IGC_SRRCTL_BSIZEHDR_MASK, \
       |                                         ^~~~~~~~~~
drivers/net/ethernet/intel/igc/igc_main.c:647:19: note: in expansion of 
macro ‘IGC_SRRCTL_BSIZEHDR’
   647 |         srrctl |= IGC_SRRCTL_BSIZEHDR(IGC_RX_HDR_LEN);
       |


For 6.3 on-wards we have the following include chain:

In file included from ./include/net/xdp.h:11,
                  from ./include/linux/netdevice.h:43,
                  from ./include/linux/if_vlan.h:10,
                  from drivers/net/ethernet/intel/igc/igc_main.c:6:

I think <linux/bitfield.h> is available "by accident" and your mainline 
patch
is faulty. igc_base.h now depends on bitfield.h but you forgot to 
include it.

How do we deal with that? I think it should be fixed in mainline as 
well.

I fear that adding the missing include in igc_base.h within the backport
breaks any further auto-backporting for the igc driver as patches might
not apply cleanly when stable diverges from mainline.

Florian

> 
> Will you do it for 5.15 and 6.2 as well?
> 
> Thanks & Regards
> Siang