[U-Boot] [PATCH 00/13] dm: DM_FLAG_PRE_RELOC flag clean up

Sat Nov 3 09:48:35 UTC 2018

Hi Simon,

On Sat, Nov 3, 2018 at 2:08 PM Simon Glass <sjg at chromium.org> wrote:
>
> Hi Bin,
>
> On 1 November 2018 at 20:25, Bin Meng <bmeng.cn at gmail.com> wrote:
> > On Sun, Oct 28, 2018 at 9:31 PM Adam Ford <aford173 at gmail.com> wrote:
> >>
> >> On Wed, Oct 24, 2018 at 8:32 AM Bin Meng <bmeng.cn at gmail.com> wrote:
> >> >
> >> > When a driver declares DM_FLAG_PRE_RELOC flag, it wishes to be
> >> > bound before relocation. However due to a bug in the DM core,
> >> > the flag only takes effect when devices are statically declared
> >> > via U_BOOT_DEVICE(). This bug has been fixed recently by commit
> >> > "dm: core: Respect drivers with the DM_FLAG_PRE_RELOC flag in
> >> > lists_bind_fdt()", but with the fix, it has a side effect that
> >> > all existing drivers that declared DM_FLAG_PRE_RELOC flag will
> >> > be bound before relocation now. This may expose potential boot
> >> > failure on some boards due to insufficient memory during the
> >> > pre-relocation stage.
> >> >
> >> > To mitigate this potential impact, the following changes are
> >> > implemented:
> >> >
> >> > - Remove DM_FLAG_PRE_RELOC flag in the driver, if the driver
> >> >   only supports configuration from device tree (OF_CONTROL)
> >> > - Keep DM_FLAG_PRE_RELOC flag in the driver only if the device
> >> >   is statically declared via U_BOOT_DEVICE()
> >> > - Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check, for
> >> >   drivers that support both statically declared devices and
> >> >   configuration from device tree
> >> >
> >> > This series should be applied on top of u-boot-dm/master, for
> >> > v2018.11 release.
> >> >
> >> >
> >> > Bin Meng (13):
> >> >   arm: stm32mp: Remove DM_FLAG_PRE_RELOC flag
> >> >   clk: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   gpio: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   i2c: omap24xx: Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check
> >> >   mmc: omap: Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check
> >> >   pinctrl: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   ram: bmips: Remove DM_FLAG_PRE_RELOC flag
> >> >   timer: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   serial: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   sysreset: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   video: simplefb: Remove DM_FLAG_PRE_RELOC flag
> >> >   watchdog: Remove DM_FLAG_PRE_RELOC flag in various drivers
> >> >   dm: doc: Update description of pre-relocation support
> >> >
> >>
> >> This works just fine for me on the am3517_evm and the omap3_logic boards.
> >>
> >> Tested-by Adam Ford <aford173 at gmailcom>
> >>
> >
> > Thanks Adam and Stephen's testing.
> >
> > Simon,
> >
> > Looks we don't have too much time before release, would you please
> > test and send the PR?
> >
> > Another series (http://patchwork.ozlabs.org/project/uboot/list/?series=70686)
> > needs to be pulled in to unblock x86 too.
>
> I had assumed we could wait to the next release.
>
> Could you please explain what you are wanting me to do here?

Short version:
As I mentioned in this series' cover letter, "This series should be
applied on top of u-boot-dm/master, for v2018.11 release.". The other
x86 series should be applied for this release too.

The long story:

In [1] I said: "It looks that I have to send out a fix to correct
Tegra in this release now, and leave other clean ups in next
release.", was because I think the clean up changes are massive and
only Stephen reported the Tegra was broken by previous series [2]
which was applied in *u-boot-dm/master* so initially I only wanted to
send out the Tegra fixes. However later Stefan reported in [3] that
some x86 boards just don't boot with *u-boot/mater*. Then I had a look
and suggested adding DM_FLAG_PRE_RELOC flag to x86 CPU drivers, which
was the x86 fixes series [4] I mentioned above. However the issue is
that without my fix in series [2], the x86 fix just doesn't work. Then
I mentioned that in [5] I said "I spent some time to clean up all
driver usage about DM_FLAG_PRE_RELOC flag" and it should fix Tegra
(reported) as well as other potential (un-reported) broken.

[1] https://lists.denx.de/pipermail/u-boot/2018-October/345085.html
[2] http://patchwork.ozlabs.org/project/uboot/list/?series=70150&state=*&q=&archive=both
[3] https://lists.denx.de/pipermail/u-boot/2018-October/344266.html
[4] http://patchwork.ozlabs.org/project/uboot/list/?series=70686
[5] https://lists.denx.de/pipermail/u-boot/2018-October/345479.html

Note both my previous series [2] and x86 fix series [4] are attempting
to fix the side effect brought up by c0434407b595 ("board_f: Use
static print_cpuinfo if CONFIG_CPU is active") which was part of the
MPC83xx CPU uclass driver support. So the root cause is the MPC83xx
changes. But I am not sure if we can revert that patch easily now, as
I suspect many later commits are dependent on that one, and we may
break some more stuff if we revert that. Up to now, I see some
'Tested-by' tags were provided for this series, I think we are good to
go.

Does this make sense?

Regards,
Bin