| Message ID | 20190619172949.4522-2-mathieu.poirier@linaro.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | 514e5150e7c6b247d7a473f935fc49d6f194688b |
| Headers | show |
| Series | coresight: next v5.2-rc5 | expand |
On Wed, Jun 19, 2019 at 11:29:05AM -0600, Mathieu Poirier wrote: > Unify amongst sink drivers how the AUX ring buffer head is communicated > to user space. That way the same algorithm in user space can be used to > determine where the latest data is and how much of it to access. > > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Tested-by: Leo Yan <leo.yan@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etb10.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c > index 4ee4c80a4354..60e753b1768d 100644 > --- a/drivers/hwtracing/coresight/coresight-etb10.c > +++ b/drivers/hwtracing/coresight/coresight-etb10.c > @@ -548,13 +548,14 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev, > writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); > > /* > - * In snapshot mode we have to update the handle->head to point > - * to the new location. > + * In snapshot mode we simply increment the head by the number of byte > + * that were written. User space function cs_etm_find_snapshot() will ^^ two spaces? :) happens everywhere you cut/pasted this comment. Not a big deal...
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 4ee4c80a4354..60e753b1768d 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -548,13 +548,14 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev, writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); /* - * In snapshot mode we have to update the handle->head to point - * to the new location. + * In snapshot mode we simply increment the head by the number of byte + * that were written. User space function cs_etm_find_snapshot() will + * figure out how many bytes to get from the AUX buffer based on the + * position of the head. */ - if (buf->snapshot) { - handle->head = (cur * PAGE_SIZE) + offset; - to_read = buf->nr_pages << PAGE_SHIFT; - } + if (buf->snapshot) + handle->head += to_read; + __etb_enable_hw(drvdata); CS_LOCK(drvdata->base); out: