Hi Patrick,
On 12 October 2018 at 09:26, Patrick Delaunay patrick.delaunay@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.delaunay@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.
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.
Regards, Simon