From 4c8d90e39bb9b60102b5c26e3e1dec6a84e9f6b2 Mon Sep 17 00:00:00 2001 From: Mathieu Poirier Date: Thu, 9 May 2019 15:47:49 -0600 Subject: coresight: etb10: Properly set AUX buffer head in snapshot mode Unify amongst sink drivers how the AUX ring buffer head is communicated to user space. That way the same algorithm in cs_etm_find_snapshot() can be used to determine where the latest data is and how much of it to access. Signed-off-by: Mathieu Poirier --- 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 + * 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: -- cgit v1.2.3