linux-kernel - Re: [PATCH v2 01/19] dt-bindings: spi: dw: Add Tx/Rx DMA properties

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

Message-ID: <20200515154308.7s3wauq5edwj437y@mobilestation>
Date:   Fri, 15 May 2020 18:43:08 +0300
From:   Serge Semin <Sergey.Semin@...kalelectronics.ru>
To:     Mark Brown <broonie@...nel.org>
CC:     Serge Semin <fancer.lancer@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Rob Herring <robh+dt@...nel.org>,
        Georgy Vlasov <Georgy.Vlasov@...kalelectronics.ru>,
        Ramil Zaripov <Ramil.Zaripov@...kalelectronics.ru>,
        Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Paul Burton <paulburton@...nel.org>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Arnd Bergmann <arnd@...db.de>,
        Allison Randal <allison@...utok.net>,
        Gareth Williams <gareth.williams.jx@...esas.com>,
        <linux-mips@...r.kernel.org>,
        Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@...el.com>,
        <linux-spi@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 01/19] dt-bindings: spi: dw: Add Tx/Rx DMA properties

On Fri, May 15, 2020 at 01:27:15PM +0100, Mark Brown wrote:
> On Fri, May 15, 2020 at 02:51:51PM +0300, Andy Shevchenko wrote:
> > On Fri, May 15, 2020 at 01:47:40PM +0300, Serge Semin wrote:
> 
> > > Since commit 22d48ad7bfac ("spi: dw: Add Elkhart Lake PSE DMA support")
> > > the spi-dw-mid.c module supports a platform DMA engine handling the DW APB
> > > SSI controller requests. Lets alter the DW SPI bindings file to accept the
> > > Rx and Tx DMA line specifiers.
> 
> > I'm wondering if these properties are implied by the SPI generic one?
> > (forgive me if I'm not understanding all DT schema relations)
> 
> Which SPI generic DMA bindings are you thinking of here?  There aren't
> any in spi-controller.yaml.

There are default schemas in the dt-core, which defines the dmas and dma-names
type, but the exact naming and number of phandler+identifiers are implementation
specific. So it's either supposed to be implemented on the generic SPI controller
basis (like in someplace of spi-controller.yaml) or in individual controllers DT
schema. As Mark said we don't have any DMA properties definition in the generic
SPI controller schema (spi-controller.yaml), so the particular SPI controllers
DT schemas have got their own DMA properties declared. Most of them BTW use the
same naming as we do here: "rx" and "tx", but some alas don't.

-Sergey