From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta0.migadu.com (out-173.mta0.migadu.com [91.218.175.173]) (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 721A233B6DC for ; Fri, 19 Dec 2025 17:22:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766164980; cv=none; b=WYiXvjqy8FUscxafE5KHRKPbc0mN8E30uYBNoMKwdvw7pp3fIg9OU7Aw9KUtBTEMB3kTC0TbG5GjDlyEC2AS+huL2KL/KwMMw6Xkl8TUpLGP/p65tP4kOoyX6PHGpZm0npQZuwsYKLGYA549kpOYb39CqFH+iNWFdmOQAxjjpws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766164980; c=relaxed/simple; bh=TYzNQ0isiTWkokeom4SbhziOp8ml3d5CiaE+CSoVQFY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rmbMwi8adBsOwTj/Wi5Yrwc4+QFjjVQHNXQAmzocZamhlwH6oaENhnk/NeejNsLoYnWeEHYiZVY1IBXZACFWlQXBS49vESLjz7fMayspOcgVfI1Y/9nzcMJ8VpR54pGprC6w2edkjaQAxHKqaac3XgiSgCBWbRyBffPHxRB9vDs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=DnNiYVsG; arc=none smtp.client-ip=91.218.175.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="DnNiYVsG" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1766164971; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a0lJL/SNLjbeVra6hhUj+h/q0KnBWqBFK5+UFeVFEuI=; b=DnNiYVsGky7iooT3a3nbKu5co/4qCd4S7rqhODuK5kCpnBQh5UpnE1ScWokGbVRhrIIpis /FzlGEtu/lAmJr7Bz95Nys0lrCiaI1RBhR+ZZ2HahYqCE1ay3xkO0Cbd7TIfxWGdUuF2xn N5kxIKAWf4layWeXsM+9hoy0/G1ZJ4M= From: Sean Anderson To: Manivannan Sadhasivam , Lorenzo Pieralisi , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Bartosz Golaszewski Cc: linux-pci@vger.kernel.org, Chen-Yu Tsai , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski , Manivannan Sadhasivam , Brian Norris , Niklas Cassel , Chen-Yu Tsai , Krishna Chaitanya Chundru , Alex Elder , Sean Anderson Subject: [PATCH 2/3] PCI/pwrctrl: Add appropriate delays for slot power/clocks Date: Fri, 19 Dec 2025 12:22:21 -0500 Message-Id: <20251219172222.2808195-2-sean.anderson@linux.dev> In-Reply-To: <20251219172222.2808195-1-sean.anderson@linux.dev> References: <39e025bd-50f4-407d-8fd4-e254dbed46b2@linux.dev> <20251219172222.2808195-1-sean.anderson@linux.dev> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Each of the PCIe electromechanical specifications requires a delay between when power and clocks are stable and when PERST is released. Delay for the specified time before continuing with initialization. If there are no power supplies/clock, skip the associated delay as we assume that they have been initialized by the bootloader (and that booting up to this point has taken longer than the delay). Signed-off-by: Sean Anderson --- drivers/pci/pwrctrl/slot.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/pci/pwrctrl/slot.c b/drivers/pci/pwrctrl/slot.c index 3320494b62d8..1c56fcd49f2b 100644 --- a/drivers/pci/pwrctrl/slot.c +++ b/drivers/pci/pwrctrl/slot.c @@ -5,6 +5,7 @@ */ #include +#include #include #include #include @@ -31,6 +32,7 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev) { struct pci_pwrctrl_slot_data *slot; struct device *dev = &pdev->dev; + unsigned long delay = 0; struct clk *clk; int ret; @@ -64,6 +66,17 @@ static int pci_pwrctrl_slot_probe(struct platform_device *pdev) "Failed to enable slot clock\n"); } + if (slot->num_supplies) + /* + * Delay for T_PVPERL. This could be reduced to 1 ms/50 ms + * (T_PVPGL) for Mini/M.2 slots. + */ + delay = 100000; + else if (clk) + /* Delay for T_PERST-CLK (100 us for all slot types) */ + delay = 100; + + fsleep(delay) pci_pwrctrl_init(&slot->ctx, dev); ret = devm_pci_pwrctrl_device_set_ready(dev, &slot->ctx); -- 2.35.1.1320.gc452695387.dirty