[PATCH 1/9] bus: ti-sysc: Fix timekeeping_suspended warning on resume

Tony Lindgren
2021-09-21T10:01:31Z

On resume we can get a warning at kernel/time/timekeeping.c:824 for
timekeeping_suspended.

Let's fix this by adding separate functions for sysc_poll_reset_sysstatus()
and sysc_poll_reset_sysconfig() and have the new functions handle also
timekeeping_suspended.

If iopoll at some point supports timekeeping_suspended, we can just drop
the custom handling from these functions.

Fixes: d46f9fbec719 ("bus: ti-sysc: Use optional clocks on for enable and wait for softreset bit")
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
drivers/bus/ti-sysc.c | 65 +++++++++++++++++++++++++++++++++++--------
1 file changed, 53 insertions(+), 12 deletions(-)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -17,6 +17,7 @@
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
+#include <linux/timekeeping.h>
#include <linux/iopoll.h>

#include <linux/platform_data/ti-sysc.h>
@@ -223,37 +224,77 @@ static u32 sysc_read_sysstatus(struct sysc *ddata)
return sysc_read(ddata, offset);
}

-/* Poll on reset status */
-static int sysc_wait_softreset(struct sysc *ddata)
+static int sysc_poll_reset_sysstatus(struct sysc *ddata)
{
- u32 sysc_mask, syss_done, rstval;
- int syss_offset, error = 0;
-
- if (ddata->cap->regbits->srst_shift < 0)
- return 0;
-
- syss_offset = ddata->offsets[SYSC_SYSSTATUS];
- sysc_mask = BIT(ddata->cap->regbits->srst_shift);
+ int error, retries;
+ u32 syss_done, rstval;

if (ddata->cfg.quirks & SYSS_QUIRK_RESETDONE_INVERTED)
syss_done = 0;
else
syss_done = ddata->cfg.syss_mask;

- if (syss_offset >= 0) {
+ if (likely(!timekeeping_suspended)) {
error = readx_poll_timeout_atomic(sysc_read_sysstatus, ddata,
rstval, (rstval & ddata->cfg.syss_mask) ==
syss_done, 100, MAX_MODULE_SOFTRESET_WAIT);
+ } else {
+ retries = MAX_MODULE_SOFTRESET_WAIT;
+ while (retries--) {
+ rstval = sysc_read_sysstatus(ddata);
+ if ((rstval & ddata->cfg.syss_mask) == syss_done)
+ return 0;
+ udelay(2); /* Account for udelay flakeyness */
+ }
+ error = -ETIMEDOUT;
+ }

- } else if (ddata->cfg.quirks & SYSC_QUIRK_RESET_STATUS) {
+ return error;
+}
+
+static int sysc_poll_reset_sysconfig(struct sysc *ddata)
+{
+ int error, retries;
+ u32 sysc_mask, rstval;
+
+ sysc_mask = BIT(ddata->cap->regbits->srst_shift);
+
+ if (likely(!timekeeping_suspended)) {
error = readx_poll_timeout_atomic(sysc_read_sysconfig, ddata,
rstval, !(rstval & sysc_mask),
100, MAX_MODULE_SOFTRESET_WAIT);
+ } else {
+ retries = MAX_MODULE_SOFTRESET_WAIT;
+ while (retries--) {
+ rstval = sysc_read_sysconfig(ddata);
+ if (!(rstval & sysc_mask))
+ return 0;
+ udelay(2); /* Account for udelay flakeyness */
+ }
+ error = -ETIMEDOUT;
}

return error;
}

+/* Poll on reset status */
+static int sysc_wait_softreset(struct sysc *ddata)
+{
+ int syss_offset, error = 0;
+
+ if (ddata->cap->regbits->srst_shift < 0)
+ return 0;
+
+ syss_offset = ddata->offsets[SYSC_SYSSTATUS];
+
+ if (syss_offset >= 0)
+ error = sysc_poll_reset_sysstatus(ddata);
+ else if (ddata->cfg.quirks & SYSC_QUIRK_RESET_STATUS)
+ error = sysc_poll_reset_sysconfig(ddata);
+
+ return error;
+}
+
static int sysc_add_named_clock_from_child(struct sysc *ddata,
const char *name,
const char *optfck_name)
--
2.33.0