> -----Original Message----- > From: Sascha Hauer [mailto:s.hauer@xxxxxxxxxxxxxx] > Sent: Friday, June 22, 2018 1:50 PM > To: A.s. Dong <aisheng.dong@xxxxxxx> > Cc: Rob Herring <robh@xxxxxxxxxx>; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > dongas86@xxxxxxxxx; kernel@xxxxxxxxxxxxxx; shawnguo@xxxxxxxxxx; > Fabio Estevam <fabio.estevam@xxxxxxx>; dl-linux-imx <linux- > imx@xxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; > devicetree@xxxxxxxxxxxxxxx > Subject: Re: [PATCH V2 2/4] dt-bindings: arm: fsl: add mu binding doc > > On Thu, Jun 21, 2018 at 05:11:33PM +0000, A.s. Dong wrote: > > Hi Sascha, > > > > > -----Original Message----- > > > From: Sascha Hauer [mailto:s.hauer@xxxxxxxxxxxxxx] > > > Sent: Thursday, June 21, 2018 3:47 PM > > > To: Rob Herring <robh@xxxxxxxxxx> > > > Cc: A.s. Dong <aisheng.dong@xxxxxxx>; linux-arm- > > > kernel@xxxxxxxxxxxxxxxxxxx; dongas86@xxxxxxxxx; > > > kernel@xxxxxxxxxxxxxx; shawnguo@xxxxxxxxxx; Fabio Estevam > > > <fabio.estevam@xxxxxxx>; dl-linux- imx <linux-imx@xxxxxxx>; Mark > > > Rutland <mark.rutland@xxxxxxx>; devicetree@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH V2 2/4] dt-bindings: arm: fsl: add mu binding > > > doc > > > > > > On Wed, Jun 20, 2018 at 01:43:10PM -0600, Rob Herring wrote: > > > > On Sun, Jun 17, 2018 at 08:49:47PM +0800, Dong Aisheng wrote: > > > > > The Messaging Unit module enables two processors within the SoC > > > > > to communicate and coordinate by passing messages (e.g. data, > > > > > status and control) through the MU interface. > > > > > > > > > > Cc: Shawn Guo <shawnguo@xxxxxxxxxx> > > > > > Cc: Sascha Hauer <kernel@xxxxxxxxxxxxxx> > > > > > Cc: Fabio Estevam <fabio.estevam@xxxxxxx> > > > > > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > > > > > Cc: Mark Rutland <mark.rutland@xxxxxxx> > > > > > Cc: devicetree@xxxxxxxxxxxxxxx > > > > > Signed-off-by: Dong Aisheng <aisheng.dong@xxxxxxx> > > > > > --- > > > > > v1->v2: > > > > > * typo fixes > > > > > * remove status property > > > > > * remove imx6&7 compatible string which may be added later for > > > > > the generic mailbox binding > > > > > > > > > > Note: Because MU used by SCU is not implemented as a mailbox > > > > > driver, Instead, they're provided in library calls to gain higher > performance. > > > > > > > > Using a binding doesn't mean you have to use an OS's subsystem. > > > > > > > > What needs higher performance? What's the performance difference? > > > Why > > > > can't the mailbox framework be improved? > > > > > > From what I see the performance is improved by polling the interrupt > > > registers rather than using interrupts. > > > I see no reason though why this can't be implemented with the > > > mailbox framework as is. > > > > > > > I thought you've agreed to not write generic MU(mailbox) driver for SCU. > > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw > ww > > .spinics.net%2Flists%2Farm- > kernel%2Fmsg650217.html&data=02%7C01%7Caish > > > eng.dong%40nxp.com%7Cfb1c9e5d6eff453207a908d5d803f139%7C686ea1d3 > bc2b4c > > > 6fa92cd99c5c301635%7C0%7C0%7C636652433808619368&sdata=vOFbr%2BSJ > 1tkY5F > > 8ha1wrxk3RMVxI4lzKkidD9cK%2Bl9A%3D&reserved=0 > > But seems it's still not quite certain... > > My suggestion was that we change the compatible of the MU unit to > something that the SCU driver matches. But since we do not do that and > instead use a fsl,imx8qxp-mu compatible for the MU we have to come up > with a MU driver that handles both the SCU case and the regular usecase. > Otherwise we'll end up with a generic driver attaching to the device you are > using under the hoods. > Do you think checking mbox-cells can work? E.g. SCU MU mbox-cells should be 0 while general purpose MU are 1. Regards Dong Aisheng > Sascha > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | > https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fww > w.pengutronix.de%2F&data=02%7C01%7Caisheng.dong%40nxp.com%7Cfb1 > c9e5d6eff453207a908d5d803f139%7C686ea1d3bc2b4c6fa92cd99c5c301635%7 > C0%7C0%7C636652433808619368&sdata=AYkDI3ubpKuxfKvmsvM8d65suEAkf > 3h9Tq5KZdJxoNY%3D&reserved=0 | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
