On Mon, 2014-10-13 at 16:30 +0100, Ben Hutchings wrote:
> On Sat, 11 Oct 2014 11:37:31 +0100 Ian Campbell <i...@debian.org> wrote:
> > On Thu, 2014-09-18 at 00:17 +0100, Ian Campbell wrote:
> > > The xgene_ahci driver requires phy-xgene in order to be able to function
> > > (i.e. to mount rootfs). It was not included in the
> > > initramfs by default. Adding it to /etc/initramfs-tools/modules allowed
> > > the system to boot but ideally this would happen
> > > automatically.
> >
> > I also have a similar issue on the arndale platform which requires
> > i2c-s3c2410 and phy-exynos5250-sata to be listed
> > in /etc/initramfs-tools/modules in order to boot from the SATA disk.
> > (I've a feeling a different non-overlapping set will be required to boot
> > from MMC, but I'll have to perform that experiment later).
>
> Uh... so an *internal* PHY is controlled over I2C? That's a bit crazy
> but perhaps this IP block is also to be usable as an external PHY.
Actually, I think the i2c here is used to talk to a power regulator of
some sort and is unrelated to the phy (it's just that both are needed).
I made the i2c device built-in yesterday for just that reason.
> > It seems that at least with current kernels there is no way to trace
> > from a block device back to the set of clocks, regulators and phys which
> > it needs. Yet I expect it is likely we will see this sort of thing on
> > other platforms too (especially arm ones).
> >
> > I'm wondering if we ought to include
> > kernel/drivers/{clk,i2c,phy,regulator}/*.ko in the base set of modules
> > (at least for MODULES=most)?
> >
> > For the current armmp kernel those are:
> > 276K i2c/
> > 24K clk/
> > 160K regulator/
> > 124K phy/
> > 584K total
> >
> > Or maybe just include the ones which are needed by various platforms on
> > an ad-hoc basis? (by listing in auto_add_modules). That might have less
> > overall impact (since not all of those modules are needed for boot) but
> > does mean we need to play whack-a-mole as new platforms arrive which use
> > a different set of clk controllers etc.
>
> I think we should do this for all but I2C adapters. For any platform
> where we build clk, phy or regulator drivers we can probably expect to
> need them at boot. The same is not generally true for I2C adapters.
>
> I would also add gpio and pinctrl to the list.
Agreed.
> > We could start building more of these modules into the kernel
> > statically. Same whack-a-mole issue as the above though.
> >
> > I'm leaning towards an adhoc list in auto_add_modules. I'll knock up a
> > patch to that affect unless I hear some objections.
>
> I'm objecting as I don't think this is appropriate in auto_add_modules.
Understood.
> > > I've had a dig through /sys looking for something which would link the
> > > AHCI driver to the phy driver, but I couldn't find
> > > anything. If you have some ideas/clues where to look I'd be happy to have
> > > another dig. In the meantime I've attached the output
> > > of "find /sys -ls".
>
> I think the only way to do that is to look at the Device Tree, and I
> don't fancy doing that to initramfs-tools. Even then I'm not sure how
> much you can get from a DTB as it doesn't have explicit type
> information.
Yeah, it's the only way I can think of and I still think we don't want
to go down this route.
> How about putting the weird dependencies in hidden_dep_add_modules?
>
> > I've attached the same for arndale (for what its worth...)
> >
> > Ian.
>
> Here are my generic changes, untested as I don't have such boards to
> test with.
I'm at LinuxCon at the minute, but I'll give this a go as soon as the
talks schedule and my remote access to the systems allows.
> They aren't going to cover i2c-s3c2410 (I think) or
> USB-PHYs.
>
> For USB-PHYs, if MODULES=most then we would do:
> copy_modules_dir kernel/drivers/usb/phy
> or if MODULES=dep then:
> add_loaded_modules 'phy[-_]*'
Sounds like a plausible plan.
> Ben.
>
> ---
> Subject: hook-functions: Add modules for various important device types
>
> Storage and networking devices may depend on PHYs that aren't clearly
> linked to them in the device model, so add those drivers. If
> MODULES=most then add all of them. Note this doesn't cover USB-PHY
> drivers, only generic PHY drivers.
>
> On ARM systems without useful firmware we may also need to
> do a lot more chip/board configuration, so also add clk,
> gpio, pinctrl and regulator drivers.
>
> If MODULES=most then add all drivers built from the corresponding
> source directories. If MODULES=dep then add drivers for the visible
> devices in these classes. As clk and regulator don't have real device
> classes but do have driver names beginning with common prefixes, add
> modules based on the current loaded or built-in modules matching these
> prefixes.
>
> Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
> ---
> hook-functions | 42 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/hook-functions b/hook-functions
> index 2a421cf..9a5155e 100644
> --- a/hook-functions
> +++ b/hook-functions
> @@ -230,6 +230,28 @@ sys_walk_modalias()
> done
> }
>
> +# Copy all loaded or built-in modules matching the given pattern.
> +# Pattern mustn't include directory or '.ko' suffix but should use
> +# '[-_]' to allow for differences in naming between /sys/module and
> +# modules.builtin.
> +add_loaded_modules()
> +{
> + local pattern="$1"
> + local module
> + for module in /sys/module/$pattern; do
> + if [ -d "$module" ]; then
> + manual_add_modules $(basename $module)
> + fi
> + done
> + while read module; do
> + case "$module" in
> + */$pattern.ko)
> + manual_add_modules $(basename $module .ko)
> + ;;
> + esac
> + done < <(cat 2>/dev/null /lib/modules/$(uname -r)/modules.builtin)
> +}
> +
> # find and only copy root relevant modules
> dep_add_modules()
> {
> @@ -417,6 +439,19 @@ dep_add_modules()
> root_dev_path=$(readlink -f /sys/block/${block}/device)
> sys_walk_mod_add ${root_dev_path}
>
> + # sys walk some important device classes
> + for class in gpio phy regulator; do
> + for device in /sys/class/$class/*; do
> + device="$(readlink -f "$device")" \
> + && sys_walk_mod_add "$device"
> + done
> + done
> +
> + # clk and pinctrl devices are outside the device model (!) so
> + # match loaded modules by name
> + add_loaded_modules 'clk[-_]*'
> + add_loaded_modules 'pinctrl[-_]*'
> +
> # catch old-style IDE
> if [ -e /sys/bus/ide/devices/ ]; then
> sys_walk_modalias ${root_dev_path}
> @@ -489,6 +524,13 @@ auto_add_modules()
> hid-speedlink.ko hid-tivo.ko hid-twinhan.ko \
> hid-uclogic.ko hid-wacom.ko hid-waltop.ko \
> hid-wiimote.ko hid-zydacron.ko
> +
> + # Any of these might be needed by other drivers
> + copy_modules_dir kernel/drivers/clk
> + copy_modules_dir kernel/drivers/gpio
> + copy_modules_dir kernel/drivers/phy
> + copy_modules_dir kernel/drivers/pinctrl
> + copy_modules_dir kernel/drivers/regulator
> ;;
> net)
> copy_modules_dir kernel/drivers/net \
>
>
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