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 228DF78F29; Wed, 12 Mar 2025 16:16:01 +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=1741796162; cv=none; b=FtPomc7+o2C8VuqqBqSP3kFSj2K+UL97qu78MCp/Ml5TaoVmmCnR+F5gYBSupCEeiCvHxmeiX+NlfMqx1cTeZ8QXX9D5z38yXXypvZpVWWWljaaKvkx9EuO/ymarA2uLloHJdDI1U+CZjDI2E30emb7gT31kCz/maSQu43XjLuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741796162; c=relaxed/simple; bh=VsNryCp6Jdy8Cj9W96kO7ltsyTKRP2vUyvO8MTRIRCA=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=K66pd0pgK5CrW+mor17LcAT4pXNe1HkKLqUDt5kApzHLxsbXY1aPJasRlx1wcPxX2xQ5s/ueiIrC4FC1hROdL4oDqjWl8MP7Lri1NzFm2Qta/1ZkkzRN0y+7wiz5yS28wgN6vsvGMnf9DBVs6+38fJ6bRfrr2IKaby5CZPInMFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ltpF4bv2; 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="ltpF4bv2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67DDDC4CEEA; Wed, 12 Mar 2025 16:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741796161; bh=VsNryCp6Jdy8Cj9W96kO7ltsyTKRP2vUyvO8MTRIRCA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=ltpF4bv2tpgig/rLF/SWUcRuVcjvjoqZTAwgDD/ab0SRZVZNFMNz/pO2uKoKFdUZ3 Efa7P5+PybmQOFHqmjcy+GO9MJyiAtGOYfr+mrGhlQpC7/AuJ9lGqOhXLihiXLnT/6 Tr/U34cIicPdZye4F1wPbcYYZNmQi9jSuLORnyM8fsy/2kkE/iVqElEgCVK/Ffm8F7 01PQdXAtnn/gCdy0zkV60RsSHtz2V4JgT6B5WM00VL29bZHnuFvCp8zH4ma+HBw7h6 J8Vcp02yuuuib4zPHSES5zqgX+d2N3xlacNeY4YPx6wiOVy8l/3OSk4Xj1JX7VN1mf D+5gS6kD2oJ2Q== Date: Wed, 12 Mar 2025 11:16:00 -0500 From: Bjorn Helgaas To: Siddharth Vadapalli , Matt Ranostay Cc: lpieralisi@kernel.org, kw@linux.com, vigneshr@ti.com, manivannan.sadhasivam@linaro.org, robh@kernel.org, bhelgaas@google.com, rogerq@kernel.org, linux-omap@vger.kernel.org, linux-pci@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, srk@ti.com Subject: Re: [PATCH] PCI: j721e: Fix the value of linkdown_irq_regfield for J784S4 Message-ID: <20250312161600.GA680640@bhelgaas> Precedence: bulk X-Mailing-List: stable@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: <20250305132018.2260771-1-s-vadapalli@ti.com> [+to Matt, author of e49ad667815d] On Wed, Mar 05, 2025 at 06:50:18PM +0530, Siddharth Vadapalli wrote: > Commit under Fixes assigned the value of 'linkdown_irq_regfield' for the > J784S4 SoC as 'LINK_DOWN' which corresponds to BIT(1). However, according > to the Technical Reference Manual and Register Documentation for the J784S4 > SoC [0], BIT(1) corresponds to "ENABLE_SYS_EN_PCIE_DPA_1" which is __NOT__ > the field for the link-state interrupt. Instead, it is BIT(10) of the > "PCIE_INTD_ENABLE_REG_SYS_2" register that corresponds to the link-state > field named as "ENABLE_SYS_EN_PCIE_LINK_STATE". I guess the reason we want this is that on J784S4, we ignore actual link-down interrupts (and we don't write STATUS_CLR_REG_SYS_2 to clear the interrupt indication, so maybe there's an interrupt storm), and we think some other interrupt (DPA_1, whatever that is) is actually a link-down interrupt? > Hence, set 'linkdown_irq_regfield' to the macro 'J7200_LINK_DOWN' which > expands to BIT(10) and was first defined for the J7200 SoC. Other SoCs > already reuse this macro since it accurately represents the link-state > field in their respective "PCIE_INTD_ENABLE_REG_SYS_2" register. > > [0]: https://www.ti.com/lit/zip/spruj52 Thanks for the spec URL. Can you include a relevant section number? I searched for some of this stuff but couldn't find it. Since I have low confidence that the URL will be valid after a few years, I wish the spec also had a human-readable name and revision number. But maybe the alphabet soup or "SPRUJ52D", "revised July 2024" is all we can hope for. > Fixes: e49ad667815d ("PCI: j721e: Add TI J784S4 PCIe configuration") > Cc: stable@vger.kernel.org > Signed-off-by: Siddharth Vadapalli > --- > > Hello, > > This patch is based on commit > 48a5eed9ad58 Merge tag 'devicetree-fixes-for-6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux > of the master branch of Linux. > > Patch has been tested on J784S4-EVM, validating that disconnecting an > Endpoint Device connected to J784S4-EVM results in the following message > on the J784S4-EVM: > j721e-pcie 2900000.pcie: LINK DOWN! > which wasn't seen earlier. > > Regards, > Siddharth. > > drivers/pci/controller/cadence/pci-j721e.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c > index 0341d51d6aed..1da9d9918d0d 100644 > --- a/drivers/pci/controller/cadence/pci-j721e.c > +++ b/drivers/pci/controller/cadence/pci-j721e.c > @@ -376,13 +376,13 @@ static const struct j721e_pcie_data j784s4_pcie_rc_data = { > .mode = PCI_MODE_RC, > .quirk_retrain_flag = true, > .byte_access_allowed = false, > - .linkdown_irq_regfield = LINK_DOWN, > + .linkdown_irq_regfield = J7200_LINK_DOWN, > .max_lanes = 4, > }; > > static const struct j721e_pcie_data j784s4_pcie_ep_data = { > .mode = PCI_MODE_EP, > - .linkdown_irq_regfield = LINK_DOWN, > + .linkdown_irq_regfield = J7200_LINK_DOWN, > .max_lanes = 4, > }; > > -- > 2.34.1 >