linux-kernel - Re: [GIT PULL] ARM: SoC fixes for v5.10, part 3

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: <20201130225459.GB1551@shell.armlinux.org.uk>
Date:   Mon, 30 Nov 2020 22:54:59 +0000
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Doug Anderson <dianders@...omium.org>,
        Arnd Bergmann <arnd@...nel.org>, SoC Team <soc@...nel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>
Subject: Re: [GIT PULL] ARM: SoC fixes for v5.10, part 3

On Mon, Nov 30, 2020 at 10:22:58AM -0800, Linus Torvalds wrote:
> > I guess the question is: why is static assignment of numbers not an
> > acceptable solution to the problem?  It gives us the desired fixed
> > numbers and automatically avoids all weird probe ordering / dependency
> > problems.
> 
> I think that if this had been done originally, it would probably be fine.

It was not done originally, because the original structure of the MMC
bus was:

host controller ---+--- card 1
                   +--- card 2
		   +--- card 3
		   ...

So one host controller could be connected to multiple different cards,
and the bus has a way to detect each card individually. This means we
had no idea how many cards would be connected to any one controller,
and it was entirely sensible to allocate MMC block devices in the order
we discovered the cards.

The SD specification, this became limited to just one card per
controller to allow for faster speeds.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!