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 B20E3CD8CA8 for ; Sun, 14 Jun 2026 04:26:55 +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:Content-Transfer-Encoding: Content-Type:MIME-Version: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:In-Reply-To:References:List-Owner; bh=XFGLMoBlVOgugds4B4DTTXS16Xixz4tT84fPGswN8Ic=; b=oerW7SyoYSvCdy0VpTD+UdEJ2+ Gp+mYgMU/ivlxxqltX0dcQWzanEpBwIXaNAFiXGUhjLw/VF4AZz10I/q0Jscy+q5husJfvLf5COyR b/yGEmZkTryN7LIiPea4D9OkOawxkuWmZfHdaH/0xeaxcjKnPxr6uzSx8R9r31g0dy4jy6hPtIlgr wQ4+hyYW4pT+At+71M0QU+yw1m4MLrCqjm+vYyOq5/Ib+cGZ5ioYZ4O7R0GGNDFgkaaaFFlVUpiVn 4I5NzfdIfdhPd765/GYocmecpWDdUGsDPaOXYpiJ+t8tpF5V2fyea0veUa//lArCC2A48xcpkKvqm IcqShQ5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wYcQr-0000000CjRZ-2MLE; Sun, 14 Jun 2026 04:26:49 +0000 Received: from ferryfair.com ([103.227.96.30]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wYcQo-0000000CjR3-3ncN; Sun, 14 Jun 2026 04:26:48 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=ferryfair.com; s=s1; h=Content-Transfer-Encoding:Content-Type:MIME-Version: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=XFGLMoBlVOgugds4B4DTTXS16Xixz4tT84fPGswN8Ic=; b=RVv1mLtCj7GQkC/xFp3coEbf81 NINRuosnmUR+QpY7o8iQE9BjzYFLWUfeEdsSGZfn56xW+L8mmAOs6lCG0xRLeLRBiETAifyaTD+fd 4P3wgPmn+/F4/1H2WIP+Ok9OLwtpPjsIeX9Xw2tDbpILg7GKO5DaNRFggvjQ9SGWIKVw/qcKybpAF 9kk3jdaQdKoJ2A/bpZDa5X1rNbCWU/DIvr7A0qnzD4mCjmtzMOJ9cYYrN4AT5J8CHRR4RJxZnVug7 cnnK9RFsMA1YMeCpHnndDzIVEVnKp47Kky3NcM4IYl44uG6rPNracRHUCg1CP+o+eURNU1cC0TjyM JjjxUoAw==; Received: from console.gl-inet.com ([192.168.0.1] helo=slick.ferryfair.com) by ferryfair.com with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.99.3) (envelope-from ) id 1wYcQV-0000000009z-3bVo; Sun, 14 Jun 2026 09:56:27 +0530 Date: Sun, 14 Jun 2026 09:56:26 +0530 From: gowtham To: yue.wang@Amlogic.com, lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org Cc: robh@kernel.org, bhelgaas@google.com, neil.armstrong@linaro.org, khilman@baylibre.com, jbrunet@baylibre.com, martin.blumenstingl@googlemail.com, linux-pci@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PULL] PCI: meson: Fix PERST# timing by asserting reset before LTSSM enable Message-ID: <20260614095626.7afb7c04@slick.ferryfair.com> Organization: FerryFair X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260613_212646_956598_4355EC11 X-CRM114-Status: UNSURE ( 7.80 ) X-CRM114-Notice: Please train this message. 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 The following changes since commit bb532bfaf7919c7c98caab81864e9ce2646e11e3: Linux 7.0.11 (2026-06-01 17:54:55 +0200) are available in the Git repository at: https://github.com/GowthamKudupudi/linux.git tags/meson-pcie-warm-reset-linux-7.0.y for you to fetch changes up to 852811b11795ee389ea6a953ed0db69b76722469: PCI: meson: Fix PERST# timing by asserting reset before LTSSM enable (2026-06-14 09:41:01 +0530) ---------------------------------------------------------------- PCI: meson: Fix PERST# timing by asserting reset before LTSSM enable On warm reboot, the PCIe controller's LTSSM starts link training immediately if PERST# is already deasserted from the previous boot. The driver then pulses PERST# for only 500us, which is too short to properly reset the endpoint device that has already started training. Fix by moving the PERST# assert/deassert pulse BEFORE enabling LTSSM, so the endpoint gets a clean reset cycle before link training begins. This was found on Amlogic G12B (A311D) with NVMe on an M.2 slot. Cold boot worked because POR held PERST# low; warm reboot did not. The fix was confirmed on a Banana Pi CM4 with Waveshare IO base board. ---------------------------------------------------------------- Gowtham Kudupudi (1): PCI: meson: Fix PERST# timing by asserting reset before LTSSM enable drivers/pci/controller/dwc/pci-meson.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)