Re: [PATCH] riscv: dts: sophgo: add initial Milk-V Duo S board device tree

[Jisheng Zhang <jszhang@kernel.org>]

On Wed, Apr 10, 2024 at 09:24:40AM +0800, Inochi Amaoto wrote:
> On Tue, Apr 09, 2024 at 03:08:17PM +0200, Michael Opdenacker wrote:
> > Hi Inochi
> > 
> > On 4/9/24 at 14:27, Inochi Amaoto wrote:
> > > On Tue, Apr 09, 2024 at 01:13:32PM +0100, Conor Dooley wrote:
> > > > On Tue, Apr 09, 2024 at 03:17:35PM +0800, Inochi Amaoto wrote:
> > > > > On Tue, Apr 09, 2024 at 08:45:04AM +0200, michael.opdenacker@bootlin.com wrote:
> > > > > > From: Michael Opdenacker <michael.opdenacker@bootlin.com>
> > > > > > 
> > > > > > This adds initial support for the Milk-V Duo S board
> > > > > > (https://milkv.io/duo-s), enabling the serial port and
> > > > > > read-only SD card support, allowing to boot Linux to the
> > > > > > command line.
> > > > > > 
> > > > > Hi Michael,
> > > > > 
> > > > > I think your patch losts the board binding and have wrong compatiable.
> > > > > Also, the SD can have rw support with proper property. See link [1]
> > > > > (need 'disable-wp').
> > > > [1] doesn't go anywhere useful.
> > > > 
> > > This is my fault, I copied the wrong url. The right patch is
> > > https://lore.kernel.org/r/20240217144826.3944-1-jszhang@kernel.org.
> > 
> > 
> > No problem, I found out.
> > I confirm that using the "disable-wp;" property does the trick to make the
> > MMC writable.
> > 
> > However, it wasn't mentioned in the above URL...
> > 
> > By the way, do I really need those under &sdhci0?
> > 
> > + bus-width = <4>; + no-1-8-v; + no-mmc; + no-sdio;
> > 
> > My board looks happy so far without them ;-)

setting the correct bus-width is necessary for better performance
no-1-8-v can be removed, but it doesn't harm anything because
the board doesn't supply 1.8v

no-mmc and no-sdio to make the probe a bit quicker

> 
> FYI, Jisheng. Could you share some suggestions?
> 
> > Thanks again for your help
> > Cheers
> > Michael.
> > 
> > -- 
> > Michael Opdenacker, Bootlin
> > Embedded Linux and Kernel engineering
> > https://bootlin.com
> >