Hi Doug,

During suspend-resume with this change on sc7180 using latest linux-next, below warning was reported.

WARNING: CPU: 0 PID: 5324 at kernel/time/timekeeping.c:754 ktime_get+0x94/0x9c
 ktime_get+0x94/0x9c
 write_tcs_reg_sync+0x4c/0x130
 tcs_invalidate+0x64/0xa4
 rpmh_rsc_invalidate+0x20/0x38
 rpmh_flush+0x58/0x1ec
 rpmh_rsc_cpu_pm_callback+0xe4/0x144
 notifier_call_chain+0x58/0x90
 __atomic_notifier_call_chain+0x48/
 cpu_pm_notify+0x40/0x6c
 cpu_pm_enter+0x34/0x7c
 cpu_pm_suspend+0x10/0x20
 syscore_suspend+0x128/0x2a4
 suspend_devices_and_enter+0x5e0/0x8a0

This seems to be because timekeeping is already suspend by this time.

Thanks,
Maulik

On 4/15/2020 10:30 PM, Douglas Anderson wrote:
If our data still isn't there after 1 second, shout and give up.

Reported-by: Joe Perches <[email protected]>
Signed-off-by: Douglas Anderson <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
---

Changes in v3:
- The register should be hex.

Changes in v2:
- Patch ("Timeout after 1 second") new for v2.

  drivers/soc/qcom/rpmh-rsc.c | 12 +++++++-----
  1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index ce39d8399312..e09d1ada0cd2 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -10,6 +10,7 @@
  #include <linux/delay.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
+#include <linux/iopoll.h>
  #include <linux/kernel.h>
  #include <linux/list.h>
  #include <linux/module.h>
@@ -175,12 +176,13 @@ static void write_tcs_reg(const struct rsc_drv *drv, int 
reg, int tcs_id,
  static void write_tcs_reg_sync(const struct rsc_drv *drv, int reg, int tcs_id,
                               u32 data)
  {
+       u32 new_data;
+
        writel(data, tcs_reg_addr(drv, reg, tcs_id));
-       for (;;) {
-               if (data == readl(tcs_reg_addr(drv, reg, tcs_id)))
-                       break;
-               udelay(1);
-       }
+       if (readl_poll_timeout_atomic(tcs_reg_addr(drv, reg, tcs_id), new_data,
+                                     new_data == data, 1, USEC_PER_SEC))
+               pr_err("%s: error writing %#x to %d:%#x\n", drv->name,
+                      data, tcs_id, reg);
  }
/**

--
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