linux-kernel - RE: [EXT] Re: [PATCH 1/1] PCI: layerscape: Set 64-bit DMA mask

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <HE1PR0401MB233186A0CDA481B775B9B92888A29@HE1PR0401MB2331.eurprd04.prod.outlook.com>
Date:   Tue, 14 Feb 2023 21:50:51 +0000
From:   Frank Li <frank.li@....com>
To:     Sean Anderson <sean.anderson@...o.com>,
        "M.H. Lian" <minghuan.lian@....com>,
        Mingkai Hu <mingkai.hu@....com>, Roy Zang <roy.zang@....com>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Rob Herring <robh@...nel.org>,
        Krzysztof Wilczyński <kw@...ux.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        "open list:PCI DRIVER FOR FREESCALE LAYERSCAPE" 
        <linuxppc-dev@...ts.ozlabs.org>,
        "open list:PCI DRIVER FOR FREESCALE LAYERSCAPE" 
        <linux-pci@...r.kernel.org>,
        "moderated list:PCI DRIVER FOR FREESCALE LAYERSCAPE" 
        <linux-arm-kernel@...ts.infradead.org>,
        open list <linux-kernel@...r.kernel.org>
CC:     "imx@...ts.linux.dev" <imx@...ts.linux.dev>
Subject: RE: [EXT] Re: [PATCH 1/1] PCI: layerscape: Set 64-bit DMA mask

> >
> > +     /* set 64-bit DMA mask and coherent DMA mask */
> > +     if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)))
> > +             dev_warn(dev, "Failed to set 64-bit DMA mask.\n");
> 
> Isn't this mandatory? Why not dev_err_probe and return the error?

I don't think it is mandatory. If failure, dma will use swiotlb. 
Just an additional memcpy involved. 

Frank Li

> 
> --Sean
> 
> >       platform_set_drvdata(pdev, pcie);
> >
> >       ret = dw_pcie_ep_init(&pci->ep);