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SubjectRe: [PATCH v3 2/2] soc: qcom: rpmh-rsc: Timeout after 1 second in write_tcs_reg_sync()
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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 <joe@perches.com>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> ---
>
> 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);
> }
>
> /**

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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