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a="1344986" X-IronPort-AV: E=Sophos;i="6.27,170,1787036400"; d="scan'208";a="1344986" Received: from fmviesa013.fm.intel.com ([10.60.135.153]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Oct 2026 10:21:20 -0700 X-CSE-ConnectionGUID: Z0kXF4sbQEeShgBC25pcTQ== X-CSE-MsgGUID: ooYRJCglToWIM3GUM965iw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,170,1787036400"; d="scan'208";a="4939386" Received: from cpetruta-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.24]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Oct 2026 10:21:16 -0700 Date: Wed, 21 Oct 2026 20:21:13 +0300 From: Andy Shevchenko To: Vinicius Pedrosa Cc: linux-serial@vger.kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, ilpo.jarvinen@linux.intel.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev, Andre Przywara , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Enzo Adriano , stable@vger.kernel.org Subject: Re: [PATCH v2 1/4] serial: 8250_dw: Keep the BUSY-safe divisor hook when DLF is present Message-ID: References: <20261020104753.28703-1-vinicius.eduardo.pedrosa@gmail.com> <20261021100049.16504-1-vinicius.eduardo.pedrosa@gmail.com> <20261021153732.1978410-1-vinicius.eduardo.pedrosa@gmail.com> <20261021170403.2052449-1-vinicius.eduardo.pedrosa@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261021170403.2052449-1-vinicius.eduardo.pedrosa@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Wed, Oct 21, 2026 at 02:04:03PM -0300, Vinicius Pedrosa wrote: > On Wed, 21 Oct 2026, Andy Shevchenko wrote: ... > > I dunno, I prefer just a longer solution, but I don't know how big this issue > > is that we need to backport in that way (and not taking the whole series as a > > fix). > > On the severity: the IER restore comes from a7b9ce39fbe4. On the A733 I > saw hardware IER left at 0 and the console stop taking TX/RX > interrupts. I haven't tested this on hardware with a real DLF. Yes. but is it only a single device/platform affected or a big class of the devices? I assume only narrow part of them which unfortunately use DFL register offset for something else in their RTL. > Given that, how about keeping the small fix as patch 1 with the stable > tag, and putting the refactoring after it in the same series? That would > keep the fix independently backportable if needed, while mainline would > still end up with the structure you proposed. It all depends on the outcome of the above discussion. Maybe others can share their opinions, but I lean towards a series-as-a-fix rather than a bit ugly fix + proper refactoring on top. The whole approach doesn't seem to me like a pile of changes. The deduplication patch can be deferred for later actually. -- With Best Regards, Andy Shevchenko