Add comments clarifying use of the THI_STREAMID0 and THI_STREAMID1
registers.
Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
---
drivers/gpu/drm/tegra/vic.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index a3dbb8813faf..48e98a60ab6e 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -117,7 +117,19 @@ static int vic_boot(struct vic *vic)
if (spec->num_ids > 0) {
value = spec->ids[0] & 0xffff;
+ /*
+ * STREAMID0 is used for input/output buffers.
+ * Initialize it to SID_VIC in case context isolation
+ * is not enabled, and SID_VIC is used for both firmware
+ * and data buffers.
+ *
+ * If context isolation is enabled, it will be
+ * overridden by the SETSTREAMID opcode as part of
+ * each job.
+ */
vic_writel(vic, value, VIC_THI_STREAMID0);
+
+ /* STREAMID1 is used for firmware loading. */
vic_writel(vic, value, VIC_THI_STREAMID1);
}
}
--
2.30.0
