From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>, mchehab@kernel.org
Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-kernel@vger.kernel.org,
Kieran Bingham <kieran.bingham@ideasonboard.com>,
Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Subject: [PATCH v2 2/2] media: vsp1: Document max_width restriction on UDS
Date: Fri, 14 Sep 2018 15:26:52 +0100 [thread overview]
Message-ID: <20180914142652.30484-2-kieran.bingham+renesas@ideasonboard.com> (raw)
In-Reply-To: <20180914142652.30484-1-kieran.bingham+renesas@ideasonboard.com>
The UDS is currently restricted based on a partition size of 256 pixels.
Document the actual restrictions, but don't increase the implementation.
The extended partition algorithm may later choose to utilise a larger
partition size to support overlapping partitions which will improve the
quality of the output images.
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
---
drivers/media/platform/vsp1/vsp1_uds.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/media/platform/vsp1/vsp1_uds.c b/drivers/media/platform/vsp1/vsp1_uds.c
index 75c613050151..e8340de85813 100644
--- a/drivers/media/platform/vsp1/vsp1_uds.c
+++ b/drivers/media/platform/vsp1/vsp1_uds.c
@@ -342,6 +342,14 @@ static unsigned int uds_max_width(struct vsp1_entity *entity,
UDS_PAD_SOURCE);
hscale = output->width / input->width;
+ /*
+ * The maximum width of the UDS is 304 pixels. These are input pixels
+ * in the event of up-scaling, and output pixels in the event of
+ * downscaling.
+ *
+ * To support overlapping parition windows we clamp at units of 256 and
+ * the remaining pixels are reserved.
+ */
if (hscale <= 2)
return 256;
else if (hscale <= 4)
--
2.17.1
next prev parent reply other threads:[~2018-09-14 14:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-14 14:26 [PATCH v2 1/2] media: vsp1: Document max_width restriction on SRU Kieran Bingham
2018-09-14 14:26 ` Kieran Bingham [this message]
2018-09-14 14:48 ` [PATCH v2 2/2] media: vsp1: Document max_width restriction on UDS Laurent Pinchart
2018-09-14 16:56 ` Sergei Shtylyov
2018-09-14 14:48 ` [PATCH v2 1/2] media: vsp1: Document max_width restriction on SRU Laurent Pinchart
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