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Date:   Tue, 5 Dec 2023 09:55:44 +0800
From:   Dawei Li <dawei.li@shingroup.cn>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Ilpo =?utf-8?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>, jszhang@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        linux-serial <linux-serial@vger.kernel.org>,
        set_pte_at@outlook.com, stable@kernel.org
Subject: Re: [PATCH] serial: dw8250: Make DLF feature independent of
 ADDITIONAL_FEATURE
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Hi Ilpo, Andy,

On Mon, Dec 04, 2023 at 03:29:35PM +0200, Andy Shevchenko wrote:
> On Mon, Dec 04, 2023 at 03:20:09PM +0200, Ilpo J?rvinen wrote:
> > On Mon, 4 Dec 2023, Dawei Li wrote:
> > 
> > > DW apb uart databook defines couples of configuration parameters of
> 
> DW_apb_uart (as it's part of file name, or spell this fully).
> 
> > > dw8250 IP, among which there are 2 of them:
> 
> DesignWare 8250 IP
> 
> ..
> 
> > > The bug was hit when we are bringing up dw8250 IP on our hardware
> 
> Ditto.
> 
> > > platform, in which parameters are configured in such combination:
> > > - ADDTIONAL_FEATURE disabled;
> > > - FRACTIONAL_BAUD_DIVISOR_EN enabled;
> 
> ..
> 
> > The very same code change is already in tty-next (from another author).
> 
> For your convenience:
> 
> d804987153e7 ("serial: 8250_dw: Decouple DLF register check from UCV")

[sigh]

Apparently I thought tty/for-linus is the "bug fixing" branch for tty by
mistake, and didn't realize the same fix patch has been landed in tty-next
for a while.

Thanks for the update.

Anyway, I believe the fixing patch should cc stable and be getting backported?
I hit the bug on 5.10.x, it's possible the bug has been there before that.

Thanks,
   dawei

> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 
>