From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB57032D435; Thu, 22 Jan 2026 08:45:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769071520; cv=none; b=XMh/NtyzIWUOJLMwwtV9Hf9bBJijWkb11BJa+6l6ItBwWpez79HIxkFt5AvhddoCYYDxzk8+0lvUdWOI6YNsKXqNvY+I6jBm10E183T/7o0jAl1q0G0gZAF9x3sbfSR3LG+Ne/mJxBWvnUgPPC1hqo8bPddbkcJnByAGH5GV3ZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769071520; c=relaxed/simple; bh=j7g22cBbVrss28m1TSmy8QBMuJe5SKfMjovK/r1GnQ0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=emV3umfcmzo6t10y1tlot1kNy0ga9Qr8PieyCC1EECpJ7oK7sywiE3h/xHsTEVHQLahSs5uTC7RR47hbak+iOPH0Roht3XdyJsdjOHbLHMeXexwl5Y8L3V0kPHNmmHNsalP9On6HZSQusddUJfeIK96rj34qbznOFYq03Vnr/sk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ANXGV6hh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ANXGV6hh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C532EC116C6; Thu, 22 Jan 2026 08:45:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769071520; bh=j7g22cBbVrss28m1TSmy8QBMuJe5SKfMjovK/r1GnQ0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ANXGV6hhxVc9EyGxbTbeyhPSij2lj6qUjeX7IuRhfZl3uS55ERl4bs+GviwabhioF oaeYwUgJ6JQFEfKBJc7IVQlxmy82lnFbJa5l/JrfUopOX4UAFrjzWNgYzpyUDZWymx kERWLBLICKljFAVQyMCpXu8QNBO5VHi/hJsvT5XeWPfBUAiWwLIUAkxbgbGtTysflz 1a7qFPvRpyhDaaMHKo0tIWVF75AQ9+gI622rka1MSxtX0nKHpVfWoX7AOcSbf11Eo8 JfvjYlhSHAVei7NbkNQSuCFYZ+ULNKkWNUhguSXEV2haFfT8AwyviGlbIevRxHuqY/ SbqECoysAFxUw== Date: Thu, 22 Jan 2026 09:45:13 +0100 From: Niklas Cassel To: Koichiro Den Cc: Manivannan Sadhasivam , bhelgaas@google.com, kwilczynski@kernel.org, frank.li@nxp.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v8 0/5] PCI: endpoint: BAR subrange mapping support Message-ID: References: <20260115084928.55701-1-den@valinux.co.jp> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hello Koichiro, On Thu, Jan 22, 2026 at 10:52:31AM +0900, Koichiro Den wrote: > > > > In this series you didn't add a consumer of this subrange mapping, which I > > believe is the epf-vntb driver [1]. Even so I don't see a justification of why > > the BAR needs to be split into multiple subranges. Can you explain that? > > Yes, the first consumer I have in mind is epf-vntb / remote eDMA-backed NTB > work referenced in [1]. Another consumer in your RFC series is pci-epf-test, specifically: [RFC PATCH v4 35/38] PCI: endpoint: pci-epf-test: Add pci_epf_test_next_free_bar() helper [RFC PATCH v4 36/38] PCI: endpoint: pci-epf-test: Add remote eDMA-backed mode [RFC PATCH v4 37/38] misc: pci_endpoint_test: Add remote eDMA transfer test mode [RFC PATCH v4 38/38] selftests: pci_endpoint: Add remote eDMA transfer coverage where the pci-epf-test exports the eDMA registers (using subranges) over a BAR, and then in the host side driver, calls dw_edma_probe() on this subrange and uses the host side driver to control the eDMA residing in the endpoint. Most of your patches in [RFC PATCH v4 35/38] have NTB prefix. Would it not be possible to simply include patches 35-38 in this series, so we actually have a consumer, or do you need some other patches as well? E.g., perhaps [RFC PATCH v4 01/38] dmaengine: dw-edma: Export helper to get integrated register window Would also be required? Kind regards, Niklas