[LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.

[LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.

[Alexey Brodkin]

Hi Claudiu,

Could you please comment on the question from Hauke below?

On Sat, 2018-01-27@16:36 +0100, Hauke Mehrtens wrote:
> Does the arc CPU also need some special handling like some MIPS CPUs:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bbc25bee37d2b32cf3a1fab9195b6da3a185614a

-Alexey

[LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.

[Claudiu Zissulescu]

Hi,

The compiler generates calls to special functions (like the one in question _multi3) if it doesn?t have a way how to solve it (via compiler backend rules). This function is implemented by the libgcc which will have a default method to address the functionality in question.
Now, from the link which you gave me, I understand users are not very happy with the _multi3 implementation (128 bit multiplication) in MIPS cores, therefore, they come up with an patched implementation. In ARC backend we try to address these issues, but if there is a problem, I will be happy to fix it.
Anyhow, if you see any issue with code gen (improvements/bugs), I would recommend you to send it over and I will spend some time in fixing them directly in the compiler.

Cheers,
Claudiu

> -----Original Message-----
> From: Alexey Brodkin
> Sent: Monday, January 29, 2018 2:38 PM
> To: Claudiu Zissulescu <claziss at synopsys.com>
> Cc: john at phrozen.org; lede-dev at lists.infradead.org; hauke at hauke-m.de;
> Evgeniy.Didin at synopsys.com; linux-snps-arc at lists.infradead.org
> Subject: Re: [LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.
> 
> Hi Claudiu,
> 
> Could you please comment on the question from Hauke below?
> 
> On Sat, 2018-01-27@16:36 +0100, Hauke Mehrtens wrote:
> > Does the arc CPU also need some special handling like some MIPS CPUs:
> >
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i
> d=bbc25bee37d2b32cf3a1fab9195b6da3a185614a
> 
> -Alexey

[LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.

[Evgeniy Didin]

Hello Hauke,

There are two patches, which solves problem with undefined "Abort":
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/comm
it/?id=7c2c11b208be09c156573fc0076b7b3646e05219
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/comm
it/?id=dc8635b78cd8669c37e230058d18c33af7451ab1

These patches are applied in Linux 4.15 ver.

I have placed these patches in target/linux/generic/backport-4.14 and
build finished without errors.
 
I expect these patches will be backported in upstream 4.14 branch
anytime soon. Until these patches are accepted should I add them with 
separate patch or should I add them in patch-series with kernel version
update for archs38?

Best regards,
Evgeniy Didin

[LEDE-DEV] [PATCH] archs38: bump kernel to 4.14.

[Hauke Mehrtens]

On 01/29/2018 04:35 PM, Evgeniy Didin wrote:
> Hello Hauke,
> 
> There are two patches, which solves problem with undefined "Abort":
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/comm
> it/?id=7c2c11b208be09c156573fc0076b7b3646e05219
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/comm
> it/?id=dc8635b78cd8669c37e230058d18c33af7451ab1
> 
> These patches are applied in Linux 4.15 ver.
> 
> I have placed these patches in target/linux/generic/backport-4.14 and
> build finished without errors.
>  
> I expect these patches will be backported in upstream 4.14 branch
> anytime soon. Until these patches are accepted should I add them with 
> separate patch or should I add them in patch-series with kernel version
> update for archs38?

Please create a separate patch which adds these to patches to
target/linux/generic/backport-4.14

I haven't seen them in the 4.14 stable queue:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-4.14

You could write to the stable mailing list to get this backported to
stable kernel 4.14, see this for details:
https://github.com/torvalds/linux/blob/master/Documentation/process/stable-kernel-rules.rst

Hauke