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 5.4-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-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 12f6e8d9335cb2f5408e42ed3d3838eb427784f8
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 f9ff6d433dfe..d59e1ca9990b 100644
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -602,6 +602,51 @@ 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)
@@ -826,6 +871,10 @@ 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);
