On Wed, Jul 22, 2020 at 06:20:29PM +0100, Suzuki K Poulose wrote:
TPIU driver access the device before the coresight device is registered. In other words, before the drvdata->csdev is valid. Thus, we need to make sure that the csdev_access is valid for both the invocations. Switch to using the csdev_access directly instead of relying on availability of drvdata->csdev.
I'm not sure all of the above is needed and based on the wording I could easily see this patch being selected for stable backport, which would be a mistak.
The gist of this patch is that we are moving to the access abstraction and the changelog should reflect that.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com
drivers/hwtracing/coresight/coresight-tpiu.c | 30 +++++++++----------- 1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c index 7ef7649f48ad..84ff4bf5d3b8 100644 --- a/drivers/hwtracing/coresight/coresight-tpiu.c +++ b/drivers/hwtracing/coresight/coresight-tpiu.c @@ -60,49 +60,45 @@ struct tpiu_drvdata { struct coresight_device *csdev; }; -static void tpiu_enable_hw(struct tpiu_drvdata *drvdata) +static void tpiu_enable_hw(struct csdev_access *csa) {
- CS_UNLOCK(drvdata->base);
- CS_UNLOCK(csa->base);
/* TODO: fill this up */
- CS_LOCK(drvdata->base);
- CS_LOCK(csa->base);
} static int tpiu_enable(struct coresight_device *csdev, u32 mode, void *__unused) {
- struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
- tpiu_enable_hw(drvdata);
- tpiu_enable_hw(&csdev->access); atomic_inc(csdev->refcnt); dev_dbg(&csdev->dev, "TPIU enabled\n"); return 0;
} -static void tpiu_disable_hw(struct tpiu_drvdata *drvdata) +static void tpiu_disable_hw(struct csdev_access *csa) {
- CS_UNLOCK(drvdata->base);
- CS_UNLOCK(csa->base);
/* Clear formatter and stop on flush */
- writel_relaxed(FFCR_STOP_FI, drvdata->base + TPIU_FFCR);
- csdev_access_relaxed_write32(csa, FFCR_STOP_FI, TPIU_FFCR); /* Generate manual flush */
- writel_relaxed(FFCR_STOP_FI | FFCR_FON_MAN, drvdata->base + TPIU_FFCR);
- csdev_access_relaxed_write32(csa, FFCR_STOP_FI | FFCR_FON_MAN, TPIU_FFCR); /* Wait for flush to complete */
- coresight_timeout(drvdata->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0);
- coresight_timeout(csa->base, TPIU_FFCR, FFCR_FON_MAN_BIT, 0); /* Wait for formatter to stop */
- coresight_timeout(drvdata->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
- coresight_timeout(csa->base, TPIU_FFSR, FFSR_FT_STOPPED_BIT, 1);
- CS_LOCK(drvdata->base);
- CS_LOCK(csa->base);
} static int tpiu_disable(struct coresight_device *csdev) {
- struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
- if (atomic_dec_return(csdev->refcnt)) return -EBUSY;
- tpiu_disable_hw(drvdata);
- tpiu_disable_hw(&csdev->access);
dev_dbg(&csdev->dev, "TPIU disabled\n"); return 0; @@ -152,7 +148,7 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id) desc.access.base = base;
Any reason for introducing the above in patch 02? I would have done that as part of this patch... Also part of this patch I would remove drvdata::base since it is no longer needed.
I'm out of time for today - I will continue tomorrow.
Regards, Mathieu
/* Disable tpiu to support older devices */
- tpiu_disable_hw(drvdata);
- tpiu_disable_hw(&desc.access);
pdata = coresight_get_platform_data(dev); if (IS_ERR(pdata)) -- 2.24.1