Re: [PATCHv2 3/4] coresight: replicator: Reset replicator if context is lost

Hi Sai,

On Tue, 19 May 2020 at 14:36, Sai Prakash Ranjan saiprakash.ranjan@codeaurora.org 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.

---

.../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;
  

};

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;On HolidayOn Holiday }

•   if (fwnode_property_present(dev_fwnode(dev),
  

•                               "qcom,replicator-loses-context"))
  

•           drvdata->check_idfilter_val = true;
  

•   dev_set_drvdata(dev, drvdata);
  
    pdata = coresight_get_platform_data(dev);
  

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

Suggested-by is just fine - I didn't actually try out my suggested code after all!

Reviewed-by Mike Leach mike.leach@linaro.org