This is a note to let you know that I've just added the patch titled bus: ti-sysc: Probe for l4_wkup and l4_cfg interconnect devices first to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bus-ti-sysc-probe-for-l4_wkup-and-l4_cfg-interconnec.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f30798a7f06dc65203e03c7ffcb1cb9816e6cbfc Author: Tony Lindgren <tony@xxxxxxxxxxx> Date: Mon Mar 8 11:35:07 2021 +0200 bus: ti-sysc: Probe for l4_wkup and l4_cfg interconnect devices first [ Upstream commit 4700a00755fb5a4bb5109128297d6fd2d1272ee6 ] We want to probe l4_wkup and l4_cfg interconnect devices first to avoid issues with missing resources. Otherwise we attempt to probe l4_per devices first causing pointless deferred probe and also annoyingh renumbering of the MMC devices for example. Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index 3d74f237f005..9e535336689f 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -635,6 +635,51 @@ static int sysc_parse_and_check_child_range(struct sysc *ddata) return 0; } +/* Interconnect instances to probe before l4_per instances */ +static struct resource early_bus_ranges[] = { + /* am3/4 l4_wkup */ + { .start = 0x44c00000, .end = 0x44c00000 + 0x300000, }, + /* omap4/5 and dra7 l4_cfg */ + { .start = 0x4a000000, .end = 0x4a000000 + 0x300000, }, + /* omap4 l4_wkup */ + { .start = 0x4a300000, .end = 0x4a300000 + 0x30000, }, + /* omap5 and dra7 l4_wkup without dra7 dcan segment */ + { .start = 0x4ae00000, .end = 0x4ae00000 + 0x30000, }, +}; + +static atomic_t sysc_defer = ATOMIC_INIT(10); + +/** + * sysc_defer_non_critical - defer non_critical interconnect probing + * @ddata: device driver data + * + * We want to probe l4_cfg and l4_wkup interconnect instances before any + * l4_per instances as l4_per instances depend on resources on l4_cfg and + * l4_wkup interconnects. + */ +static int sysc_defer_non_critical(struct sysc *ddata) +{ + struct resource *res; + int i; + + if (!atomic_read(&sysc_defer)) + return 0; + + for (i = 0; i < ARRAY_SIZE(early_bus_ranges); i++) { + res = &early_bus_ranges[i]; + if (ddata->module_pa >= res->start && + ddata->module_pa <= res->end) { + atomic_set(&sysc_defer, 0); + + return 0; + } + } + + atomic_dec_if_positive(&sysc_defer); + + return -EPROBE_DEFER; +} + static struct device_node *stdout_path; static void sysc_init_stdout_path(struct sysc *ddata) @@ -863,6 +908,10 @@ static int sysc_map_and_check_registers(struct sysc *ddata) if (error) return error; + error = sysc_defer_non_critical(ddata); + if (error) + return error; + sysc_check_children(ddata); error = sysc_parse_registers(ddata);