From: Dave Gerlach <[email protected]>
Add a debugfs option to allow configurable halting of the wkup_m3
during suspend at the last possible point before low power mode entry.
This condition can only be resolved through JTAG and advancing beyond
the while loop in a8_lp_ds0_handler [1]. Although this hangs the system
it forces the system to remain active once it has been entirely
configured for low power mode entry, allowing for register inspection
through JTAG to help in debugging transition errors.
Halt mode can be set using the enable_off_mode entry under wkup_m3_ipc
in the debugfs.
[1] https://git.ti.com/cgit/processor-firmware/ti-amx3-cm3-pm-firmware/tree/src/pm_services/pm_handlers.c?h=08.02.00.006#n141
Suggested-by: Brad Griffis <[email protected]>
Signed-off-by: Dave Gerlach <[email protected]>
[dfustini: add link for a8_lp_ds0_handler() in ti-amx3-cm3-pm-firmware]
Signed-off-by: Drew Fustini <[email protected]>
---
drivers/soc/ti/wkup_m3_ipc.c | 79 +++++++++++++++++++++++++++++++++++-
include/linux/wkup_m3_ipc.h | 2 +
2 files changed, 80 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c
index c35eaecf4ab4..19bed465ad94 100644
--- a/drivers/soc/ti/wkup_m3_ipc.c
+++ b/drivers/soc/ti/wkup_m3_ipc.c
@@ -7,6 +7,7 @@
* Dave Gerlach <[email protected]>
*/
+#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
@@ -50,6 +51,9 @@
#define IPC_IO_ISOLATION_STAT_SHIFT (10)
#define IPC_IO_ISOLATION_STAT_MASK (0x1 << 10)
+#define IPC_DBG_HALT_SHIFT (11)
+#define IPC_DBG_HALT_MASK (0x1 << 11)
+
#define M3_STATE_UNKNOWN 0
#define M3_STATE_RESET 1
#define M3_STATE_INITED 2
@@ -157,6 +161,73 @@ static int wkup_m3_init_scale_data(struct wkup_m3_ipc *m3_ipc,
return ret;
}
+#ifdef CONFIG_DEBUG_FS
+static void wkup_m3_set_halt_late(bool enabled)
+{
+ if (enabled)
+ m3_ipc_state->halt = (1 << IPC_DBG_HALT_SHIFT);
+ else
+ m3_ipc_state->halt = 0;
+}
+
+static int option_get(void *data, u64 *val)
+{
+ u32 *option = data;
+
+ *val = *option;
+
+ return 0;
+}
+
+static int option_set(void *data, u64 val)
+{
+ u32 *option = data;
+
+ *option = val;
+
+ if (option == &m3_ipc_state->halt) {
+ if (val)
+ wkup_m3_set_halt_late(true);
+ else
+ wkup_m3_set_halt_late(false);
+ }
+
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(wkup_m3_ipc_option_fops, option_get, option_set,
+ "%llu\n");
+
+static int wkup_m3_ipc_dbg_init(struct wkup_m3_ipc *m3_ipc)
+{
+ m3_ipc->dbg_path = debugfs_create_dir("wkup_m3_ipc", NULL);
+
+ if (!m3_ipc->dbg_path)
+ return -EINVAL;
+
+ (void)debugfs_create_file("enable_late_halt", 0644,
+ m3_ipc->dbg_path,
+ &m3_ipc->halt,
+ &wkup_m3_ipc_option_fops);
+
+ return 0;
+}
+
+static inline void wkup_m3_ipc_dbg_destroy(struct wkup_m3_ipc *m3_ipc)
+{
+ debugfs_remove_recursive(m3_ipc->dbg_path);
+}
+#else
+static inline int wkup_m3_ipc_dbg_init(struct wkup_m3_ipc *m3_ipc)
+{
+ return 0;
+}
+
+static inline void wkup_m3_ipc_dbg_destroy(struct wkup_m3_ipc *m3_ipc)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
static void am33xx_txev_eoi(struct wkup_m3_ipc *m3_ipc)
{
writel(AM33XX_M3_TXEV_ACK,
@@ -402,7 +473,9 @@ static int wkup_m3_prepare_low_power(struct wkup_m3_ipc *m3_ipc, int state)
wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1);
wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type |
m3_ipc->vtt_conf |
- m3_ipc->isolation_conf, 4);
+ m3_ipc->isolation_conf |
+ m3_ipc->halt, 4);
+
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 6);
@@ -633,6 +706,8 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev)
goto err_put_rproc;
}
+ wkup_m3_ipc_dbg_init(m3_ipc);
+
return 0;
err_put_rproc:
@@ -644,6 +719,8 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev)
static int wkup_m3_ipc_remove(struct platform_device *pdev)
{
+ wkup_m3_ipc_dbg_destroy(m3_ipc_state);
+
mbox_free_channel(m3_ipc_state->mbox);
rproc_shutdown(m3_ipc_state->rproc);
diff --git a/include/linux/wkup_m3_ipc.h b/include/linux/wkup_m3_ipc.h
index fef0fac60f8c..26d1eb058fa3 100644
--- a/include/linux/wkup_m3_ipc.h
+++ b/include/linux/wkup_m3_ipc.h
@@ -36,6 +36,7 @@ struct wkup_m3_ipc {
int vtt_conf;
int isolation_conf;
int state;
+ u32 halt;
unsigned long volt_scale_offsets;
const char *sd_fw_name;
@@ -46,6 +47,7 @@ struct wkup_m3_ipc {
struct wkup_m3_ipc_ops *ops;
int is_rtc_only;
+ struct dentry *dbg_path;
};
struct wkup_m3_wakeup_src {
--
2.32.0
Hi Drew Fustini,
On Sun, 1 May 2022 20:32:12 -0700, Drew Fustini wrote:
> From: Dave Gerlach <[email protected]>
>
> Add a debugfs option to allow configurable halting of the wkup_m3
> during suspend at the last possible point before low power mode entry.
> This condition can only be resolved through JTAG and advancing beyond
> the while loop in a8_lp_ds0_handler [1]. Although this hangs the system
> it forces the system to remain active once it has been entirely
> configured for low power mode entry, allowing for register inspection
> through JTAG to help in debugging transition errors.
>
> [...]
I have applied the following to branch ti-drivers-soc-next on [1].
Thank you!
[1/1] soc: ti: wkup_m3_ipc: Add debug option to halt m3 in suspend
commit: 2a21f9e6d9a408dbd09a01caf5fff42c2f70fa82
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent up the chain during
the next merge window (or sooner if it is a relevant bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
[1] git://git.kernel.org/pub/scm/linux/kernel/git/ti/linux.git
--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D