+ Update the function syscon_node_to_regmap() to force bound on syscon uclass and directly use the list of device from DM. + Remove the static list syscon_list.
This patch avoid issue (crash) when syscon_node_to_regmap() is called before and after reallocation (list content is invalid).
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com --- Hi
This patch is a modified (after Simon Glass review) and rebased version on v2018.11-rc3 for [U-Boot] syscon: reset node list syscon_list after relocation http://patchwork.ozlabs.org/patch/983139/
This patch correct a crash see on v2018.11-rc1 with my board stm32mp1 for the command "reset", reproduced on v2018.11-rc3.
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)
I have a crash here because the pointer syscon_list.next is invalid.
This patch solves the issue by using DM list for syscon uclass.
Tested on my board, the initial issue is solved and I check the behavior with dm_dump_all(): the RCC driver is not binded/probed as syscon uclass by default (checked with dm tree) and correctly bounded and probed when it is necessary (before relocation: print_resetinfo() or after relocation for command reset).
Regards
Patrick
Changes in v2: - minor update after Simon review (remove variable ofnode and add one comment)
drivers/core/syscon-uclass.c | 55 ++++++++++++++------------------------------ 1 file changed, 17 insertions(+), 38 deletions(-)
diff --git a/drivers/core/syscon-uclass.c b/drivers/core/syscon-uclass.c index 303e166..3864f13 100644 --- a/drivers/core/syscon-uclass.c +++ b/drivers/core/syscon-uclass.c @@ -123,52 +123,31 @@ U_BOOT_DRIVER(generic_syscon) = { * The syscon node can be bound to another driver, but still works * as a syscon provider. */ -static LIST_HEAD(syscon_list); - -struct syscon { - ofnode node; - struct regmap *regmap; - struct list_head list; -}; - -static struct syscon *of_syscon_register(ofnode node) +struct regmap *syscon_node_to_regmap(ofnode node) { - struct syscon *syscon; + struct udevice *dev, *parent; 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);
- syscon = malloc(sizeof(*syscon)); - if (!syscon) - return ERR_PTR(-ENOMEM); + /* bound to driver with same ofnode or to root if not found */ + if (device_find_global_by_ofnode(node, &parent)) + parent = dm_root();
- ret = regmap_init_mem(node, &syscon->regmap); - if (ret) { - free(syscon); + /* 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); - } - - list_add_tail(&syscon->list, &syscon_list); - - return syscon; -}
-struct regmap *syscon_node_to_regmap(ofnode node) -{ - struct syscon *entry, *syscon = NULL; - - list_for_each_entry(entry, &syscon_list, list) - if (ofnode_equal(entry->node, node)) { - syscon = entry; - break; - } - - if (!syscon) - syscon = of_syscon_register(node); - - if (IS_ERR(syscon)) - return ERR_CAST(syscon); + ret = device_probe(dev); + if (ret) + return ERR_PTR(ret);
- return syscon->regmap; + return syscon_get_regmap(dev); }