From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from layka.disroot.org (layka.disroot.org [178.21.23.139]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DDD1D2E36EB; Tue, 22 Jul 2025 00:35:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.21.23.139 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753144519; cv=none; b=Us5lPnIH2ocbNUrUg8f2fy0kjP40Y9zivwYYiv46F1muWzUimemnHGyB/bIzEVm0rCVQJNP/6ig9uYLQydMOVlMNb1Ukxml3tUNEBxMVRcUmiGW4b9tL093fjIQGFgIw9mzX0qvDrx27zX2mY03+/bMFzmqQTrKAN5Oqq5d2t34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753144519; c=relaxed/simple; bh=NVJSthHoVBfvJ0DprsxJsTID3or77ayMtN3PtiGsObQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fVHD/rrwWpeRUgPginqCkBA2H0V7wAlMPkXSarB9HDUYVPjVpYFsWBRjajtjCbzjs0tybA51lkXRSJFhijlAAHQXY0B501g6gG7HW2mJsDGCyzLqLMEOmlHwSHmMRRUj7gMGf+GtfhVwZsfBHdL7yYjqRnhVKXwrpeKFeaQWzt4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org; spf=pass smtp.mailfrom=disroot.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b=kuqp7Svq; arc=none smtp.client-ip=178.21.23.139 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=disroot.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=disroot.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=disroot.org header.i=@disroot.org header.b="kuqp7Svq" Received: from mail01.disroot.lan (localhost [127.0.0.1]) by disroot.org (Postfix) with ESMTP id 46DFF2082C; Tue, 22 Jul 2025 02:35:14 +0200 (CEST) X-Virus-Scanned: SPAM Filter at disroot.org Received: from layka.disroot.org ([127.0.0.1]) by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP id 2AWGV58KjTtc; Tue, 22 Jul 2025 02:35:13 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=disroot.org; s=mail; t=1753144513; bh=NVJSthHoVBfvJ0DprsxJsTID3or77ayMtN3PtiGsObQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=kuqp7SvqE3+gsACQYmTXKrC6X6J/IBJVAvyya0mbiIsDkonQbEAg4tHtU90nE2fOO maPB8WmFiNZIQBVtbQ5nZ1VKVgu8ehAoh0wGLNES47exI9ghg7zuUL54J4gtoTdMz5 tJYNXt4HOTIzqW9tNieEM2P/1o7t0VXzKJeO0orz4Bkz5+SPeuGo15x0CxAontFdWS I/D91B2ADLRNe+Bu1Ta0N7jG3yVEU8LxLvF6XW7tawKRh0QjJP2JNDny4uwpMZXphy uaoLs/SQ3vpfwD+kycJR2prgJzg5LDK+22uzpxHx+3Y2p1pbHW2o3yIcylVoF1fzU3 34If+OcvH0l6w== Date: Tue, 22 Jul 2025 00:34:46 +0000 From: Yao Zi To: Ze Huang , Alex Elder , Greg Kroah-Hartman , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Yixun Lan , Thinh Nguyen , Philipp Zabel Cc: linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, spacemit@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 2/2] usb: dwc3: add generic driver to support flattened Message-ID: References: <20250712-dwc3_generic-v6-0-cc87737cc936@linux.dev> <20250712-dwc3_generic-v6-2-cc87737cc936@linux.dev> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Jul 21, 2025 at 08:08:06PM +0800, Ze Huang wrote: > On Sun, Jul 20, 2025 at 02:34:07PM +0800, Ze Huang wrote: > > On Tue, Jul 15, 2025 at 03:50:54PM -0500, Alex Elder wrote: > > > On 7/12/25 2:49 AM, Ze Huang wrote: > > > > To support flattened dwc3 dt model and drop the glue layer, introduce the > > > > `dwc3-generic` driver. This enables direct binding of the DWC3 core driver > > > > and offers an alternative to the existing glue driver `dwc3-of-simple`. > > > > > > I'm not familiar with dwc-of-simple.c, and won't comment on > > > how this differs from that (or does not). > > > > > > Given you're implementing an alternative though, can you explain > > > in a little more detail what's different between the two? Why > > > would someone choose to use this driver rather than the other one? > > > > They are basically the same. > > > > dwc-generic use a plain dt node while dwc-of-simple will nest the dwc3 > > node as its child. > > > > Both will use dwc3_core_probe() to finish the probe process. But now we > > can simplify the process by just calling it, instead of calling > > of_platform_populate() and create another snps,dwc3 device driver. > > [...] > > > > > + ret = reset_control_assert(dwc3->resets); > > > > + if (ret) > > > > + return dev_err_probe(dev, ret, "failed to assert resets\n"); > > > > + > > > > + ret = devm_add_action_or_reset(dev, dwc3_generic_reset_control_assert, dwc3->resets); > > > > + if (ret) > > > > + return ret; > > > > > > The re-assert shouldn't be set up unless the deassert below > > > succeeds. > > > > > > > Will move behind the deassert. > > > > > > + usleep_range(10, 1000); > > > > > > This seems like a large range. You could just do msleep(1); > > > Also, can you add a comment explaining why a delay is needed, > > > and why 1 millisecond is the right amount of time to sleep? > > > > > > > I will check the range with spacemit and reply soon. > > > > the resets are asynchronous with no strict timing. But to be safe, each > reset should stay active for at least 1 µs. I’ll switch to a udelay(2) > and add comment accordingly. This may be a little farsight: do you think it's better to make the reset timing part of the of_match_data? This is more flexible and reduces future burden when introducing a new platform that comes with a different reset timing, which is a very likely case we'll face since it's a "generic" driver. > > > > + ret = reset_control_deassert(dwc3->resets); > > > > + if (ret) > > > > + return dev_err_probe(dev, ret, "failed to deassert resets\n"); > > > > + > > > > + ret = devm_clk_bulk_get_all(dwc3->dev, &dwc3->clks); > > > > + if (ret < 0) > > > > + return dev_err_probe(dev, ret, "failed to get clocks\n"); > > > > > > Call devm_clk_bulk_get_all_enabled() instead of doing the two > > > steps separately here. > > > > > > > Will do, thanks. > > > > > -Alex > Regards, Yao Zi