Hi Simon,
> From: s...@google.com <s...@google.com> On Behalf Of Simon Glass
> Sent: vendredi 19 octobre 2018 05:25
>
> Hi Patrick,
>
> On 12 October 2018 at 09:26, Patrick Delaunay <patrick.delau...@st.com>
> wrote:
> > Reset the list head after the reallocation because the list
> > syscon_list use allocated pointer and they are no more valid.
> > This patch avoid issue (crash) when syscon_node_to_regmap() is called
> > before and after reallocation.
> >
> > Signed-off-by: Patrick Delaunay <patrick.delau...@st.com>
> > ---
> > Hi
> >
> > This patch correct a crash see on v2018.11-rc1 with my board stm32mp1
> > for the command "reset".
> >
> > The crash is a side effect of 2 patches
> > 1f6ca3f42f6edf143473159297f4c515b1cf36f6
> > sysreset: syscon: update regmap access to syscon
> >
> > 23471aed5c33e104d6fa64575932577618543bec
> > board_f: Add reset status printing
> >
> > With the first patch the syscon_node_to_regmap() is called each time
> > that the class sysreset_syscon is probed.
> >
> > => in v2018.09 probe is done only when reset is requested
> >
> > NB: for stm32mp1, the node rcc_reboot in tagged pre-relocated to
> > support reset in pre-reloc phases (allow panic).
> >
> > With the second patch, U-Boot probes all the sysreset uclass in preloc
> > phase to allow to print the reset status, and the list is initialized
> > in board_f / pre-reloc:
> >
> > -> print_resetinfo
> > --> uclass_first_device_err(UCLASS_SYSRESET, &dev);
> > ---> syscon_reboot_probe()
> > ----> syscon_node_to_regmap(node)
> > -----> of_syscon_register()
> > -------> list_add_tail(&syscon->list, &syscon_list);
> >
> > During relocation, the content of syscon_list (static) is updated but
> > the list use pointers allocated by malloc in pre-reloc phasis
> >
> > And when I execute the reset command
> > -> do_reset()
> > --> reset_cpu()
> > ---> sysreset_walk_halt(SYSRESET_COLD);
> > ----> loop on device UCLASS_SYSRESET
> > -----> syscon_reboot_probe()
> > ------> syscon_node_to_regmap(node)
> > -------> list_for_each_entry(entry, &syscon_list, list)
>
> We have a similar issue with the timer - we set gd->timer to NULL in
> initr_dm().
>
> I am not 100% what is going on here, but using pre-reloc devices (i.e.
> which were set up before relocation) after relocation is bad. We need to avoid
> that.
Ok, I agree with you.
> The syscon_list struct should be in the syscon uclass, i.e. declared as
> uclass priv
> data in UCLASS_DRIVER(syscon). We should not have this as free-standard static
> data. That's not how DM works...
> So I guess Masahiro's patch needs to be adjusted.
Today, I read your comment and I start to move the list in syscon uclass priv
data (I just discovered the uclass priv data).
But after some time spent with this list, I prefer completely remove it and
have the same behavior with DM functions (as a list is already managed for the
drivers).
It is more that only a adjustment, I completely update the function
syscon_node_to_regmap():
force bound to syscon driver and probe it when the syscon driver don't yet
exist.....
=> Do you think that is a good solution ?
The function change to:
struct regmap *syscon_node_to_regmap(ofnode node)
{
struct udevice *dev;
struct udevice *parent;
ofnode ofnode = node;
int ret;
if (!uclass_get_device_by_ofnode(UCLASS_SYSCON, node, &dev))
return syscon_get_regmap(dev);
if (!ofnode_device_is_compatible(node, "syscon"))
return ERR_PTR(-EINVAL);
if (device_find_global_by_ofnode(ofnode, &parent))
parent = dm_root();
/* force bound to syscon class */
ret = device_bind_driver_to_node(parent, "syscon",
ofnode_get_name(node),
node, &dev);
if (ret)
return ERR_PTR(ret);
ret = device_probe(dev);
if (ret)
return ERR_PTR(ret);
return syscon_get_regmap(dev);
}
Tested on my board, the initial issue is sole and I check the behavior with
dm_dump_all();
It seems OK for my case (RCC driver) .
before relocation => syscon is correctly probed
Class index Probed Driver Name
-----------------------------------------
root 0 [ + ] root_drive root_driver
misc 0 [ ] stm32mp_bs |-- stm32mp_bsec
simple_bus 0 [ + ] generic_si |-- soc
serial 0 [ + ] serial_stm | |-- serial@40010000
misc 1 [ + ] stm32-rcc | |-- rcc@50000000
clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk
reset 0 [ ] stm32_rcc_ | | |-- stm32_rcc_reset
syscon 1 [ + ] syscon | | `-- rcc@50000000
<<<< SYSCON PROBED
sysreset 0 [ + ] syscon_reb | |-- rcc-reboot@50000000
mmc 0 [ ] stm32_sdmm | |-- sdmmc@58005000
blk 0 [ ] mmc_blk | | `-- sd...@58005000.blk
And it is also the case for syscon reset (when I execute the command reset)
STM32MP> reset
resetting ...
STM32MP> reset
resetting ...
Class index Probed Driver Name
-----------------------------------------
root 0 [ + ] root_drive root_driver
misc 0 [ + ] stm32mp_bs |-- stm32mp_bsec
simple_bus 0 [ + ] generic_si |-- soc
serial 0 [ + ] serial_stm | |-- serial@40010000
i2c 0 [ ] stm32f7-i2 | |-- i2c@40013000
i2c 1 [ ] stm32f7-i2 | |-- i2c@40015000
usb 0 [ ] dwc2_usb | |-- usb-otg@49000000
misc 1 [ + ] stm32-rcc | |-- rcc@50000000
clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk
reset 0 [ + ] stm32_rcc_ | | |-- stm32_rcc_reset
syscon 4 [ + ] syscon | | `-- rcc@50000000
<<<<< SYSCON
sysreset 0 [ + ] syscon_reb | |-- rcc-reboot@50000000
And the driver is not binded/probed by default (checked with dm tree)
STM32MP> dm tree
Class index Probed Driver Name
-----------------------------------------
root 0 [ + ] root_drive root_driver
misc 0 [ + ] stm32mp_bs |-- stm32mp_bsec
simple_bus 0 [ + ] generic_si |-- soc
serial 0 [ + ] serial_stm | |-- serial@40010000
i2c 0 [ ] stm32f7-i2 | |-- i2c@40013000
i2c 1 [ ] stm32f7-i2 | |-- i2c@40015000
usb 0 [ ] dwc2_usb | |-- usb-otg@49000000
misc 1 [ + ] stm32-rcc | |-- rcc@50000000
<<<<< NO SYSCON child
clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk
reset 0 [ + ] stm32_rcc_ | | `-- stm32_rcc_reset
sysreset 0 [ ] syscon_reb | |-- rcc-reboot@50000000
syscon 0 [ ] stmp32mp_s | |-- pwr@50001000
> Regards,
> Simon
Regards
Patrick
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