From 02d76a471975382ccf7f9d4b0859e00fe723265f Mon Sep 17 00:00:00 2001
From: Philipp Zabel
Date: Thu, 12 Dec 2019 15:23:27 +0100
Subject: [PATCH] media: coda: avoid hardware lockups with more than 13 capture
buffers
When decoding using the CODA internal rotator (for example NV12
capture), currently the value vb2_buf.index + CODA_MAX_FRAMEBUFFERS (19)
is written into the DEC_PIC_ROT_INDEX register. At least with firmware
version 3.1.1 this causes CODA hangups as soon as the register value
reaches 32. Instead, always write CODA_MAX_FRAMEBUFFERS.
Signed-off-by: Philipp Zabel
Signed-off-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab
---
drivers/media/platform/coda/coda-bit.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/drivers/media/platform/coda/coda-bit.c b/drivers/media/platform/coda/coda-bit.c
index 5475de1..3443396 100644
--- a/drivers/media/platform/coda/coda-bit.c
+++ b/drivers/media/platform/coda/coda-bit.c
@@ -2168,16 +2168,21 @@ static int coda_prepare_decode(struct coda_ctx *ctx)
} else {
if (dev->devtype->product == CODA_960) {
/*
- * The CODA960 seems to have an internal list of
- * buffers with 64 entries that includes the
- * registered frame buffers as well as the rotator
- * buffer output.
- *
- * ROT_INDEX needs to be < 0x40, but >
- * ctx->num_internal_frames.
+ * It was previously assumed that the CODA960 has an
+ * internal list of 64 buffer entries that contains
+ * both the registered internal frame buffers as well
+ * as the rotator buffer output, and that the ROT_INDEX
+ * register must be set to a value between the last
+ * internal frame buffers' index and 64.
+ * At least on firmware version 3.1.1 it turns out that
+ * setting ROT_INDEX to any value >= 32 causes CODA
+ * hangups that it can not recover from with the SRC VPU
+ * reset.
+ * It does appear to work however, to just set it to a
+ * fixed value in the [ctx->num_internal_frames, 31]
+ * range, for example CODA_MAX_FRAMEBUFFERS.
*/
- coda_write(dev,
- CODA_MAX_FRAMEBUFFERS + dst_buf->vb2_buf.index,
+ coda_write(dev, CODA_MAX_FRAMEBUFFERS,
CODA9_CMD_DEC_PIC_ROT_INDEX);
reg_addr = CODA9_CMD_DEC_PIC_ROT_ADDR_Y;
--
2.7.4