From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0FDB4349CD7; Fri, 17 Jul 2026 17:09:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784308199; cv=none; b=JD6xDc5h8Vn4O7ZVnDldVSiV10KPFCKUf96S5DqOm//CMoQITqWpO3zH2Z74LrJTU44NFBYPpzLR3dDFoX5LERXV+j2BCjD0NPfZgCngM/mJDj1HRmB9M/yFKuEOdfHtORE5cF9ceKwJ2tJul2+Dg1LGOaOnMk9gJlTUTsGpz8o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784308199; c=relaxed/simple; bh=ym2v4YmYfJCHRs2bjR8+AYF/V8og/2Ps/38jlnEn5mE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=avNxDOv866cphhX8jaw5z2UynkQV0TkU7Nk1jZUcaw5tteRqwzJNdKbzGMz7bVdPY/bMBIvMiqQuHOM8pE8NetQkS3JgRAy5uim8bUYna7kr2ng8y92qY5f0C7B8t8NJYM2cuERhjJjSPKEvdmEna24bRO3/YB65Hw3mf6AskcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i5TbUhyE; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i5TbUhyE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D3E11F000E9; Fri, 17 Jul 2026 17:09:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784308197; bh=vrIIp5vvuim1vMqA0JaquYGqHqFXlC/x9tIPiRIrp0w=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=i5TbUhyEKURDYC//pmORMnyZIHNvtflLPqTTUQgKjllucYKinkcQl+ssuKZrzA7nW 0n1w6zhI7AJ8gx3SWYRLm94qclZsGIEQ9CYPDjQfTiGpHLt9Ff7ggdTTeowCJZyvZT mmNL9TJt8Z4HGsobH3Avb+VLWn2yNV9cWWxBd8b16diMtjrchCYgSJTlEAAgI4EMtR aiifL/uiUt/WVKnSRKSEfa6fDxMc1TzQVBaCh2F+csc0OP+bVjd9+fe4qH0b2/tfHr XdbQCSQJDcpGeFjTha6ceq7sFcmk0kmVqlPIxSwi/mMCo0mGgQBP0XzDJPuvtj9nIW X6fVJCtnhYTmQ== Date: Fri, 17 Jul 2026 12:09:56 -0500 From: Bjorn Helgaas To: hongxing.zhu@oss.nxp.com Cc: frank.li@nxp.com, l.stach@pengutronix.de, lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org, robh@kernel.org, bhelgaas@google.com, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org, Soeren Moch , stable@vger.kernel.org, Richard Zhu Subject: Re: [PATCH v3] PCI: imx6: Keep i.MX6Q Root Port MSI capability with iMSI-RX to work around hardware bug Message-ID: <20260717170956.GC11343@bhelgaas> References: <20260717033203.2965045-1-hongxing.zhu@oss.nxp.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260717033203.2965045-1-hongxing.zhu@oss.nxp.com> On Fri, Jul 17, 2026 at 11:32:03AM +0800, hongxing.zhu@oss.nxp.com wrote: > From: Soeren Moch > > On some NXP chipsets, disabling Root Port MSI/MSI-X Capabilities blocks > MSIs originating from Endpoints from reaching the iMSI-RX controller. > > To address this hardware bug, commit 3a4e8302e72f ("PCI: imx6: Keep Root > Port MSI capability with iMSI-RX to work around hardware bug") preserves > Root Port MSI and MSI-X Capabilities on i.MX7D, i.MX8MM, and i.MX8MQ > when iMSI-RX is in use. > > The same applies to i.MX6Q, i.MX6QP and i.MX6SX. So preserve Root Port > MSI/MSI-X Capabilities there as well. > > Note that preserving these Capabilities means Root Port-originated MSIs > such as AER and PME won't be received due to separate hardware limitations. > Users may need to use workarounds such as passing the 'pcie_pme=nomsi' > command-line parameter. > > Fixes: f5cd8a929c825 ("PCI: dwc: Remove MSI/MSIX capability for Root Port if iMSI-RX is used as MSI controller") > Cc: # 7.0+ > Signed-off-by: Soeren Moch > Signed-off-by: Richard Zhu > Acked-by: Richard Zhu > Reviewed-by: Frank Li > Reviewed-by: Manivannan Sadhasivam Applied to pci/for-linus for v7.2, thank you! > --- > changes in v3: > - Extend the fix to i.MX6QP and i.MX6SX variants as well. > - Update the commit descriptions suggested by Bjorn. > > changes in v2: > - collect a-b and r-b tags > - use correct fixes tag (Manivannan) > (reference commit that introduced the bug, not the incomplete fix) > --- > drivers/pci/controller/dwc/pci-imx6.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c > index 98e1db751132a..dba27eac6bff6 100644 > --- a/drivers/pci/controller/dwc/pci-imx6.c > +++ b/drivers/pci/controller/dwc/pci-imx6.c > @@ -1995,7 +1995,8 @@ static const struct imx_pcie_drvdata drvdata[] = { > .flags = IMX_PCIE_FLAG_IMX_PHY | > IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND | > IMX_PCIE_FLAG_BROKEN_SUSPEND | > - IMX_PCIE_FLAG_SUPPORTS_SUSPEND, > + IMX_PCIE_FLAG_SUPPORTS_SUSPEND | > + IMX_PCIE_FLAG_KEEP_MSI_CAP, > .dbi_length = 0x200, > .gpr = "fsl,imx6q-iomuxc-gpr", > .ltssm_off = IOMUXC_GPR12, > @@ -2011,7 +2012,8 @@ static const struct imx_pcie_drvdata drvdata[] = { > .flags = IMX_PCIE_FLAG_IMX_PHY | > IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND | > IMX_PCIE_FLAG_SKIP_L23_READY | > - IMX_PCIE_FLAG_SUPPORTS_SUSPEND, > + IMX_PCIE_FLAG_SUPPORTS_SUSPEND | > + IMX_PCIE_FLAG_KEEP_MSI_CAP, > .gpr = "fsl,imx6q-iomuxc-gpr", > .ltssm_off = IOMUXC_GPR12, > .ltssm_mask = IMX6Q_GPR12_PCIE_CTL_2, > @@ -2026,7 +2028,8 @@ static const struct imx_pcie_drvdata drvdata[] = { > .flags = IMX_PCIE_FLAG_IMX_PHY | > IMX_PCIE_FLAG_SPEED_CHANGE_WORKAROUND | > IMX_PCIE_FLAG_SKIP_L23_READY | > - IMX_PCIE_FLAG_SUPPORTS_SUSPEND, > + IMX_PCIE_FLAG_SUPPORTS_SUSPEND | > + IMX_PCIE_FLAG_KEEP_MSI_CAP, > .dbi_length = 0x200, > .gpr = "fsl,imx6q-iomuxc-gpr", > .ltssm_off = IOMUXC_GPR12, > -- > 2.34.1 >