Messages in this thread | | | Date | Fri, 22 May 2020 23:26:23 +0530 | From | Sai Prakash Ranjan <> | Subject | Re: [PATCHv2 3/4] coresight: replicator: Reset replicator if context is lost |
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Hi Mathieu,
On 2020-05-22 23:10, Mathieu Poirier wrote: > Hi Sai, > > On Tue, May 19, 2020 at 07:06:02PM +0530, Sai Prakash Ranjan wrote: >> On some QCOM SoCs, replicators in Always-On domain loses its >> context as soon as the clock is disabled. Currently as a part >> of pm_runtime workqueue, clock is disabled after the replicator >> is initialized by amba_pm_runtime_suspend assuming that context >> is not lost which is not true for replicators with such >> limitations. So add a new property "qcom,replicator-loses-context" >> to identify such replicators and reset them. >> >> Suggested-by: Mike Leach <mike.leach@linaro.org> >> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> >> --- >> >> Added Mike's suggested by for parts other than the DT property. >> Perhaps I should add Co-developed-by Mike since the full skeletal >> was given by Mike. I can add that if required on the next version. > > I will let Mike decide what he wants to do - I'm fine either way. >
Mike was ok with suggested-by, so I will go with that.
>> >> --- >> .../coresight/coresight-replicator.c | 53 >> +++++++++++++------ >> 1 file changed, 36 insertions(+), 17 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c >> b/drivers/hwtracing/coresight/coresight-replicator.c >> index c619b456f55a..ba66160c8140 100644 >> --- a/drivers/hwtracing/coresight/coresight-replicator.c >> +++ b/drivers/hwtracing/coresight/coresight-replicator.c >> @@ -38,6 +38,7 @@ struct replicator_drvdata { >> struct clk *atclk; >> struct coresight_device *csdev; >> spinlock_t spinlock; >> + bool check_idfilter_val; > > Please add documentation for the new field, the same way other fields > are > documented. >
Sure will add that.
>> }; >> >> static void dynamic_replicator_reset(struct replicator_drvdata >> *drvdata) >> @@ -66,29 +67,43 @@ static int dynamic_replicator_enable(struct >> replicator_drvdata *drvdata, >> int inport, int outport) >> { >> int rc = 0; >> - u32 reg; >> - >> - switch (outport) { >> - case 0: >> - reg = REPLICATOR_IDFILTER0; >> - break; >> - case 1: >> - reg = REPLICATOR_IDFILTER1; >> - break; >> - default: >> - WARN_ON(1); >> - return -EINVAL; >> - } >> + u32 id0val, id1val; >> >> CS_UNLOCK(drvdata->base); >> >> - if ((readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0) == 0xff) && >> - (readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1) == 0xff)) >> + id0val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER0); >> + id1val = readl_relaxed(drvdata->base + REPLICATOR_IDFILTER1); >> + >> + /* >> + * Some replicator designs lose context when AMBA clocks are >> removed, >> + * so have a check for this. >> + */ >> + if (drvdata->check_idfilter_val && id0val == 0x0 && id1val == 0x0) >> + id0val = id1val = 0xff; >> + >> + if (id0val == 0xff && id1val == 0xff) >> rc = coresight_claim_device_unlocked(drvdata->base); >> >> + if (!rc) { >> + switch (outport) { >> + case 0: >> + id0val = 0x0; >> + break; >> + case 1: >> + id1val = 0x0; >> + break; >> + default: >> + WARN_ON(1); >> + rc = -EINVAL; >> + } >> + } >> + >> /* Ensure that the outport is enabled. */ >> - if (!rc) >> - writel_relaxed(0x00, drvdata->base + reg); >> + if (!rc) { >> + writel_relaxed(id0val, drvdata->base + REPLICATOR_IDFILTER0); >> + writel_relaxed(id1val, drvdata->base + REPLICATOR_IDFILTER1); >> + } >> + >> CS_LOCK(drvdata->base); >> >> return rc; >> @@ -239,6 +254,10 @@ static int replicator_probe(struct device *dev, >> struct resource *res) >> desc.groups = replicator_groups; >> } >> >> + if (fwnode_property_present(dev_fwnode(dev), >> + "qcom,replicator-loses-context")) >> + drvdata->check_idfilter_val = true; >> + > > The header <linux/property.h> needs to be added for function > fwnode_property_present(). >
Sure will add in next version.
> What is the clock situation with other QC components like funnels? > Have they > also been designed the same way? If so the binding should probably be > "qcom,component-loses-context", otherwise what you have suggested will > work just > fine. My goal here is to avoid having "qcom,replicator-loses-context" > and > "qcom,funnel-loses-context". >
Yes I understand it is quite ugly, but AFAIK we do not have any SoCs already released and coming in near future with such limitations in funnels or other components. So I will stick to the replicator specific property.
> Lastly, I have applied patch 1 and 2 of this set to my tree so no need > to resend > them again with the next revision. >
Thanks for reviewing these patches.
Thanks, Sai -- 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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