From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 74F9DC3ABC3 for ; Tue, 13 May 2025 14:09:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yxPA23HdKeyxkAUYpeecStgTTV+hlIZsZuM1LzpeJmg=; b=2LJQVycTvEjfCPeubsrIirdnW2 12m/oNMqvKPzIU8zr9BcuiU4FUk2w9TeXbhJfWl0zWm8NR2UubqRiKcgAVwqSvP6a6ujCPExrZJaD Jc1/U+zM4xTpj848c5txVAkn8hSqaj6wsmYWJJCmrSLAIhZG4148kfCsV8HsJpAOy4asEMe0aDjdI K+ZUtmJJVZTtzOzt3ndQD5jbwswlmFv+yMwpeuZU4wt0e8NyV2wK7K99kM0Bh9yvdSfeJdUF2lwH3 II37ttX0NgzoalQH3wuiNipCztJ1X9/TA3IeZZdoeSKOvJcWFTCyhUTCSUh5Adl0RcPuVPBKTHvd0 KbsJqDRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEqJr-0000000CZnP-2Pmk; Tue, 13 May 2025 14:09:19 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEqHk-0000000CZZX-2b5U; Tue, 13 May 2025 14:07:09 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 39DFC44E6B; Tue, 13 May 2025 14:07:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8CFAC4CEE4; Tue, 13 May 2025 14:07:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747145228; bh=14NlYj/WRG8Q0M9cGAjhUlbL7est4+1nXlxlO/Sw13M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jfyJWelTw2cvqNxTtFvNddGoQgPxSGnXDfgHyD7S1pRovdUiRF/RrEDtGkMMA9DqR 0pE2hIGsEcSog39LlatonEh8jFUsdkLIxu4cn3qQWN8jdpdH+481B3gyvxHJ2M/Xf6 XY2cAVg4GaVUqm6IJ9V7w+Sg0ZtJLI/1ftHViBLYDwssJ/39DCw04qoWn3jykvHra8 MzaSWCbobCvW2ZSYrVFLa53JUcsFuME2YlaZnGxvVNNYGY4EI2eounHeNcqtryUUOG UniSDHJRyX0NXHUCd4pd5M56pd+FakfGKY+FviDSDrJAR4WiPWyMFcLqT+CBTYYkww JzhK9J0WfRCPA== Date: Tue, 13 May 2025 16:07:02 +0200 From: Niklas Cassel To: Manivannan Sadhasivam Cc: Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Heiko Stuebner , Krishna chaitanya chundru , Wilfred Mallawa , Damien Le Moal , Hans Zhang <18255117159@163.com>, Laszlo Fiat , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v2 0/4] PCI: dwc: Link Up IRQ fixes Message-ID: References: <20250506073934.433176-6-cassel@kernel.org> <7zcrjlv5aobb22q5tyexca236gnly6aqhmidx6yri6j7wowteh@mylkqbwehak7> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7zcrjlv5aobb22q5tyexca236gnly6aqhmidx6yri6j7wowteh@mylkqbwehak7> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250513_070708_715635_89A17DA5 X-CRM114-Status: GOOD ( 23.46 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello Mani, On Tue, May 13, 2025 at 11:53:29AM +0100, Manivannan Sadhasivam wrote: > > This wait time is a grey area in the spec tbh. If the Readiness Notification > (RN) is not supported, then the spec suggests waiting 1s for the device to > become 'configuration ready'. That's why we have the 1s delay in dwc driver. > > Also, it has the below in r6.0, sec 6.6.1: > > ``` > * On the completion of Link Training (entering the DL_Active state, see § > Section 3.2 ), a component must be able to receive and process TLPs and DLLPs. > * Following exit from a Conventional Reset of a device, within 1.0 s the device > must be able to receive a Configuration Request and return a Successful > Completion if the Request is valid. This period is independent of how quickly > Link training completes. If Readiness Notifications mechanisms are used (see > § Section 6.22 .), this period may be shorter. > ``` > > As per the first note, once link training is completed, the device should be > ready to accept configuration requests from the host. So no delay should be > required. > > But the second note says that the 1s delay is independent of how quickly the > link training completes. This essentially contradicts with the above point. > > So I think it is not required to add delay after completing the LTSSM, unless > someone sees any issue. If you look at the commit message in patch 1/2, the whole reason for this series is that someone has seen an issue :) While I personally haven't seen any issue, the user reporting that commit ec9fd499b9c6 ("PCI: dw-rockchip: Don't wait for link since we can detect Link Up") regressed his system so that it can no longer mount rootfs (which is on a PLEXTOR PX-256M8PeGN NVMe SSD) clearly has seen an issue. It is possible that his device is not following the spec. I simply compared the code before and after ec9fd499b9c6, to try to figure out why it was actually working before, and came up with this, which made his device functional again. Perhaps we should add a comment above the sleep that says that this should strictly not be needed as per the spec? (And also add the same comment in the (single) controller driver in mainline which already does an msleep(PCIE_T_RRS_READY_MS).) Kind regards, Niklas From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5194BC3ABCC for ; Tue, 13 May 2025 14:09:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+xlvAlwNszDIdvnEHFpMr+f97tqLGWofRdA/l+IiBR4=; b=jWwHodUwiNctrd D/7eRPfKXpebXRYKvjfNQzqUP26kzmBf/1o/cHJ3XM+QZcoIvLl6VSWOiIu5q3ab76h3I4afj/iBC k0Ga+n70wr58Ha8Yu18qOzjFLnrGxTjX0zrxY7yQ13h78Iyd/wGZKp114MJb2hPMSmHUkXUOicjW0 tCVkn3ScEomIq1KV+TpD0cXG6urKqzQIDmujVZfv/zCo9l+DpIL7R9KM0DlAY+2FfAtDOFrAC7yD2 fGzo/zJo7ikB/plr+ircS+Xcz1j0md5jz7HST5YoycVx2ANw08pHLS0OOC1I8GJocc0y4ammdQfcY 8ocWruDIy2ETIEgb/4oA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEqJs-0000000CZnf-0WQJ; Tue, 13 May 2025 14:09:20 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uEqHk-0000000CZZX-2b5U; Tue, 13 May 2025 14:07:09 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 39DFC44E6B; Tue, 13 May 2025 14:07:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8CFAC4CEE4; Tue, 13 May 2025 14:07:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747145228; bh=14NlYj/WRG8Q0M9cGAjhUlbL7est4+1nXlxlO/Sw13M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jfyJWelTw2cvqNxTtFvNddGoQgPxSGnXDfgHyD7S1pRovdUiRF/RrEDtGkMMA9DqR 0pE2hIGsEcSog39LlatonEh8jFUsdkLIxu4cn3qQWN8jdpdH+481B3gyvxHJ2M/Xf6 XY2cAVg4GaVUqm6IJ9V7w+Sg0ZtJLI/1ftHViBLYDwssJ/39DCw04qoWn3jykvHra8 MzaSWCbobCvW2ZSYrVFLa53JUcsFuME2YlaZnGxvVNNYGY4EI2eounHeNcqtryUUOG UniSDHJRyX0NXHUCd4pd5M56pd+FakfGKY+FviDSDrJAR4WiPWyMFcLqT+CBTYYkww JzhK9J0WfRCPA== Date: Tue, 13 May 2025 16:07:02 +0200 From: Niklas Cassel To: Manivannan Sadhasivam Cc: Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Heiko Stuebner , Krishna chaitanya chundru , Wilfred Mallawa , Damien Le Moal , Hans Zhang <18255117159@163.com>, Laszlo Fiat , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v2 0/4] PCI: dwc: Link Up IRQ fixes Message-ID: References: <20250506073934.433176-6-cassel@kernel.org> <7zcrjlv5aobb22q5tyexca236gnly6aqhmidx6yri6j7wowteh@mylkqbwehak7> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7zcrjlv5aobb22q5tyexca236gnly6aqhmidx6yri6j7wowteh@mylkqbwehak7> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250513_070708_715635_89A17DA5 X-CRM114-Status: GOOD ( 23.46 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org SGVsbG8gTWFuaSwKCk9uIFR1ZSwgTWF5IDEzLCAyMDI1IGF0IDExOjUzOjI5QU0gKzAxMDAsIE1h bml2YW5uYW4gU2FkaGFzaXZhbSB3cm90ZToKPiAKPiBUaGlzIHdhaXQgdGltZSBpcyBhIGdyZXkg YXJlYSBpbiB0aGUgc3BlYyB0YmguIElmIHRoZSBSZWFkaW5lc3MgTm90aWZpY2F0aW9uCj4gKFJO KSBpcyBub3Qgc3VwcG9ydGVkLCB0aGVuIHRoZSBzcGVjIHN1Z2dlc3RzIHdhaXRpbmcgMXMgZm9y IHRoZSBkZXZpY2UgdG8KPiBiZWNvbWUgJ2NvbmZpZ3VyYXRpb24gcmVhZHknLiBUaGF0J3Mgd2h5 IHdlIGhhdmUgdGhlIDFzIGRlbGF5IGluIGR3YyBkcml2ZXIuCj4gCj4gQWxzbywgaXQgaGFzIHRo ZSBiZWxvdyBpbiByNi4wLCBzZWMgNi42LjE6Cj4gCj4gYGBgCj4gKiBPbiB0aGUgY29tcGxldGlv biBvZiBMaW5rIFRyYWluaW5nIChlbnRlcmluZyB0aGUgRExfQWN0aXZlIHN0YXRlLCBzZWUgwqcK PiBTZWN0aW9uIDMuMiApLCBhIGNvbXBvbmVudCBtdXN0IGJlIGFibGUgdG8gcmVjZWl2ZSBhbmQg cHJvY2VzcyBUTFBzIGFuZCBETExQcy4KPiAqIEZvbGxvd2luZyBleGl0IGZyb20gYSBDb252ZW50 aW9uYWwgUmVzZXQgb2YgYSBkZXZpY2UsIHdpdGhpbiAxLjAgcyB0aGUgZGV2aWNlCj4gbXVzdCBi ZSBhYmxlIHRvIHJlY2VpdmUgYSBDb25maWd1cmF0aW9uIFJlcXVlc3QgYW5kIHJldHVybiBhIFN1 Y2Nlc3NmdWwKPiBDb21wbGV0aW9uIGlmIHRoZSBSZXF1ZXN0IGlzIHZhbGlkLiBUaGlzIHBlcmlv ZCBpcyBpbmRlcGVuZGVudCBvZiBob3cgcXVpY2tseQo+IExpbmsgdHJhaW5pbmcgY29tcGxldGVz LiBJZiBSZWFkaW5lc3MgTm90aWZpY2F0aW9ucyBtZWNoYW5pc21zIGFyZSB1c2VkIChzZWUKPiDC pyBTZWN0aW9uIDYuMjIgLiksIHRoaXMgcGVyaW9kIG1heSBiZSBzaG9ydGVyLgo+IGBgYAo+IAo+ IEFzIHBlciB0aGUgZmlyc3Qgbm90ZSwgb25jZSBsaW5rIHRyYWluaW5nIGlzIGNvbXBsZXRlZCwg dGhlIGRldmljZSBzaG91bGQgYmUKPiByZWFkeSB0byBhY2NlcHQgY29uZmlndXJhdGlvbiByZXF1 ZXN0cyBmcm9tIHRoZSBob3N0LiBTbyBubyBkZWxheSBzaG91bGQgYmUKPiByZXF1aXJlZC4KPiAK PiBCdXQgdGhlIHNlY29uZCBub3RlIHNheXMgdGhhdCB0aGUgMXMgZGVsYXkgaXMgaW5kZXBlbmRl bnQgb2YgaG93IHF1aWNrbHkgdGhlCj4gbGluayB0cmFpbmluZyBjb21wbGV0ZXMuIFRoaXMgZXNz ZW50aWFsbHkgY29udHJhZGljdHMgd2l0aCB0aGUgYWJvdmUgcG9pbnQuCj4gCj4gU28gSSB0aGlu ayBpdCBpcyBub3QgcmVxdWlyZWQgdG8gYWRkIGRlbGF5IGFmdGVyIGNvbXBsZXRpbmcgdGhlIExU U1NNLCB1bmxlc3MKPiBzb21lb25lIHNlZXMgYW55IGlzc3VlLgoKSWYgeW91IGxvb2sgYXQgdGhl IGNvbW1pdCBtZXNzYWdlIGluIHBhdGNoIDEvMiwgdGhlIHdob2xlIHJlYXNvbiBmb3IgdGhpcwpz ZXJpZXMgaXMgdGhhdCBzb21lb25lIGhhcyBzZWVuIGFuIGlzc3VlIDopCgpXaGlsZSBJIHBlcnNv bmFsbHkgaGF2ZW4ndCBzZWVuIGFueSBpc3N1ZSwgdGhlIHVzZXIgcmVwb3J0aW5nIHRoYXQgY29t bWl0CmVjOWZkNDk5YjljNiAoIlBDSTogZHctcm9ja2NoaXA6IERvbid0IHdhaXQgZm9yIGxpbmsg c2luY2Ugd2UgY2FuIGRldGVjdApMaW5rIFVwIikgcmVncmVzc2VkIGhpcyBzeXN0ZW0gc28gdGhh dCBpdCBjYW4gbm8gbG9uZ2VyIG1vdW50IHJvb3Rmcwood2hpY2ggaXMgb24gYSBQTEVYVE9SIFBY LTI1Nk04UGVHTiBOVk1lIFNTRCkgY2xlYXJseSBoYXMgc2VlbiBhbiBpc3N1ZS4KCkl0IGlzIHBv c3NpYmxlIHRoYXQgaGlzIGRldmljZSBpcyBub3QgZm9sbG93aW5nIHRoZSBzcGVjLgpJIHNpbXBs eSBjb21wYXJlZCB0aGUgY29kZSBiZWZvcmUgYW5kIGFmdGVyIGVjOWZkNDk5YjljNiwgdG8gdHJ5 IHRvCmZpZ3VyZSBvdXQgd2h5IGl0IHdhcyBhY3R1YWxseSB3b3JraW5nIGJlZm9yZSwgYW5kIGNh bWUgdXAgd2l0aCB0aGlzLAp3aGljaCBtYWRlIGhpcyBkZXZpY2UgZnVuY3Rpb25hbCBhZ2Fpbi4K ClBlcmhhcHMgd2Ugc2hvdWxkIGFkZCBhIGNvbW1lbnQgYWJvdmUgdGhlIHNsZWVwIHRoYXQgc2F5 cyB0aGF0IHRoaXMKc2hvdWxkIHN0cmljdGx5IG5vdCBiZSBuZWVkZWQgYXMgcGVyIHRoZSBzcGVj PwooQW5kIGFsc28gYWRkIHRoZSBzYW1lIGNvbW1lbnQgaW4gdGhlIChzaW5nbGUpIGNvbnRyb2xs ZXIgZHJpdmVyIGluCm1haW5saW5lIHdoaWNoIGFscmVhZHkgZG9lcyBhbiBtc2xlZXAoUENJRV9U X1JSU19SRUFEWV9NUykuKQoKCktpbmQgcmVnYXJkcywKTmlrbGFzCgpfX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpMaW51eC1yb2NrY2hpcCBtYWlsaW5nIGxp c3QKTGludXgtcm9ja2NoaXBAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFk ZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LXJvY2tjaGlwCg==