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 48AB32264C0; Fri, 19 Sep 2025 10:00:39 +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=1758276040; cv=none; b=MIABZzanZBJgQKHy1aPq/B7x97oYz1utjd3+1kSASLEjIUOZvEbFzebDhs10UAbTOyfflcP+B1HOTE1rydjxbYnj6zVG0ne9By7mbZI8c3+0Jw4+GVU77e97IWnWOrMadI//GHGLHR4XKi4GqxiIPVThSDK6CoDQumHJEutrWi8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758276040; c=relaxed/simple; bh=YTJgexDyUPZARcdNN5n1Rh3wR2Moa3LhQxpJ9ovNIgU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jC8r/JLMPtOqS5+suGU5N3JptvmFrzVaxK3PlKCsg/7tIxpcOAWcN1J9ou9xkeXCSG1tzDVmwE8DxpVNNufXDpoBkcEuq+KIrP83l8B5INUhen+ggfBZ4p84celdzXshuEepH3Voj922CEszXjpgClhqtqBbY6f85bPxjtCizy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KX1F89su; 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="KX1F89su" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8987AC4CEF0; Fri, 19 Sep 2025 10:00:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758276039; bh=YTJgexDyUPZARcdNN5n1Rh3wR2Moa3LhQxpJ9ovNIgU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KX1F89su1/o7ycWJJR3Nrbd6g+ZLwbUMFxZMxSllf4zAuA8D4gm6pSmlL4QfjnorA VM1LwSqERlXXAweGYgR+IAOzgCbdyKlLEMZ9tvMIYR9akYFYjag0UNLraexDdfAOC+ m4KPFqok9veAyzYRRWMVjtx8PJOZGmypMvlaQgXBIc5r3inc3fovImTexLFi+zIOUq udtC2hAbWt+BX5mr0hb2OsbezM7NtthMsxkscQw4+8w+xB8N4mZslvFya1Nv5fNjhQ 4Pcn5TMUfkvO8by2hhN3KrXHfmS9oJJAN8CIC90d9FmcBsDQMLIZ0hjutqHadDNicE qXbzCunkIzpcQ== Date: Fri, 19 Sep 2025 19:00:38 +0900 From: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= To: Marek Vasut Cc: linux-pci@vger.kernel.org, Geert Uytterhoeven , Bjorn Helgaas , Geert Uytterhoeven , Lorenzo Pieralisi , Magnus Damm , Manivannan Sadhasivam , Rob Herring , Yoshihiro Shimoda , linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v2] PCI: rcar-gen4: Add missing 1ms delay after PWR reset assertion Message-ID: <20250919100038.GA3918632@rocinante> References: <20250918231253.189906-1-marek.vasut+renesas@mailbox.org> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250918231253.189906-1-marek.vasut+renesas@mailbox.org> Hello, [...] > Because it is the controller driver which can determine whether or not the > controller is in HSC domain based on its compatible string, add the missing > delay into the controller driver. > > This 1ms delay is documented on R-Car V4H and V4M, it is currently unclear > whether S4 is affected as well. This patch does apply the extra delay on > R-Car S4 as well. [...] > - if (!reset_control_status(dw->core_rsts[DW_PCIE_PWR_RST].rstc)) > + if (!reset_control_status(dw->core_rsts[DW_PCIE_PWR_RST].rstc)) { > reset_control_assert(dw->core_rsts[DW_PCIE_PWR_RST].rstc); > + fsleep(1000); > + } Would it be a prudent thing to do here to add a comment over the fsleep() or over the if-statement to document briefly (and for posterity) why we sleep here? Otherwise, looks good! Thank you for fixing this potential issue. Reviewed-by: Krzysztof Wilczyński Thank you, Krzysztof