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 0E5742147ED for ; Thu, 5 Jun 2025 12:28:47 +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=1749126528; cv=none; b=pzdV71Vm5fLlKrauFd2iM2ffTDVEAw0OQKgUcii7rGUlxcjiv/LTh/PIl1Ay6TLrAOWAJY203GMiPkIm4SdkwMwbfm5uAS9PqUH7Nc95qiZklusVNxX8doTtAF+MHVkTQl6KwJsen6AMNfQpaV+bGsRqg9JuaP68ziHppqUxH14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749126528; c=relaxed/simple; bh=OsTzD+oORNTzhAZmxmT/ueCMxPcm05WUBUz9VWZM/PI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nd60pUIFbVfEufSW2bfZqBR2PigZcqHhn0L1k3auSBTvzbJutgtll7A43vLQlNlLPSwUWXW/8IyXF1yZVzaXav+ltV19PxKTs4oKv8hLtFfyRPkEy58cCS4raPWxbSXM4DN2Y/WDefCpFaDfWlOWbHqio1xWWodmpHdEdYMzYT8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g2s7MXZr; 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="g2s7MXZr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80FADC4CEE7; Thu, 5 Jun 2025 12:28:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749126527; bh=OsTzD+oORNTzhAZmxmT/ueCMxPcm05WUBUz9VWZM/PI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=g2s7MXZrn6Og/9t2StYKytwNqM8xht9QkdPBaXhclk+Rpfm8jYQGfNh+/87G9Z7Aj bUjNTQDxBwTbexMFcNXzCn/g2ap8mMmhubkmnKRIcFwa7OM2PqvMrSk+Cb5DhL05VG RUNxClMieuWFyzVnIeyEAYVQVdGLK1B33ObOk+791RlcHnjPIbuKqV+TU7+ghzBphh BS/IkXrrg40u2+6oU3XMvhlPhqFNhgW7EwLTg3XwTJq+IDQPbJixpzZCQmwoPv528A /98ac8Rix/Iw+xCS0pULxLA1GOPJnaZCWjLb12W3cq0O7Q1ODGUZHPfWTnUfC9KkDR 8jNrzYlOgItEg== Date: Thu, 5 Jun 2025 14:28:41 +0200 From: Niklas Cassel To: Bjorn Helgaas Cc: Manivannan Sadhasivam , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Bjorn Helgaas , Heiko Stuebner , 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 Subject: Re: [PATCH v2 1/4] PCI: dw-rockchip: Do not enumerate bus before endpoint devices are ready Message-ID: References: <20250604184445.GA567382@bhelgaas> Precedence: bulk X-Mailing-List: linux-pci@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: <20250604184445.GA567382@bhelgaas> On Wed, Jun 04, 2025 at 01:44:45PM -0500, Bjorn Helgaas wrote: > On Wed, Jun 04, 2025 at 10:40:09PM +0530, Manivannan Sadhasivam wrote: > > > > If we add a 100 ms sleep after wait_for_link(), then I suggest that we > > > also reduce LINK_WAIT_SLEEP_MS to something shorter. > > > > No. The 900ms sleep is to make sure that we wait 1s before erroring out > > assuming that the device is not present. This is mandated by the spec. So > > irrespective of the delay we add *after* link up, we should try to detect the > > link up for ~1s. > > I think it would be sensible for dw_pcie_wait_for_link() to check for > link up more frequently, i.e., reduce LINK_WAIT_SLEEP_MS and increase > LINK_WAIT_MAX_RETRIES. > > If LINK_WAIT_SLEEP_MS * LINK_WAIT_MAX_RETRIES is for the 1.0s > mentioned in sec 6.6.1, seems like maybe we should make a generic > #define for it so we could include the spec reference and use it > across all drivers. And resolve the question of 900ms vs 1000ms. Like Bjorn mentioned, when I wrote reduce LINK_WAIT_SLEEP_MS, I simply meant that we should poll for link up more frequently. But yes, if we reduce LINK_WAIT_SLEEP_MS we should bump LINK_WAIT_MAX_RETRIES to not change the current max wait time. Bjorn, should I send something out after -rc1, or did you want to work on this yourself? Kind regards, Niklas