From: Michael Rodin <mrodin@de.adit-jv.com>
To: <niklas.soderlund@ragnatech.se>, <mchehab@kernel.org>,
<p.zabel@pengutronix.de>, <linux-media@vger.kernel.org>,
<linux-renesas-soc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: Michael Rodin <mrodin@de.adit-jv.com>,
<efriedrich@de.adit-jv.com>, <erosca@de.adit-jv.com>,
<sudipi@jp.adit-jv.com>, <akiyama@nds-osk.co.jp>
Subject: [PATCH] [RFC] media: rcar-vin: don't wait for stop state on clock lane during start of CSI2
Date: Tue, 18 Feb 2020 12:44:11 +0100 [thread overview]
Message-ID: <1582026251-21047-1-git-send-email-mrodin@de.adit-jv.com> (raw)
The chapter 7.1 "D-PHY Physical Layer Option" of the CSI2 specification
states that non-continuous clock behavior is optional, i.e. the Clock Lane
can remain in high-speed mode between the transmission of data packets.
Therefore waiting for the stop state (LP-11) on the Clock Lane is wrong and
will cause timeouts when a CSI2 transmitter with continuous clock behavior
is attached to R-Car CSI2 receiver. So wait only for the stop state on the
Data Lanes.
Signed-off-by: Michael Rodin <mrodin@de.adit-jv.com>
---
drivers/media/platform/rcar-vin/rcar-csi2.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
index faa9fb2..6d1992a 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -416,8 +416,7 @@ static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
for (timeout = 0; timeout <= 20; timeout++) {
const u32 lane_mask = (1 << priv->lanes) - 1;
- if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL) &&
- (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
+ if ((rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
return 0;
usleep_range(1000, 2000);
--
2.7.4
next reply other threads:[~2020-02-18 11:44 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 11:44 Michael Rodin [this message]
2020-02-19 17:24 ` [PATCH] [RFC] media: rcar-vin: don't wait for stop state on clock lane during start of CSI2 Jacopo Mondi
2020-02-24 14:13 ` Rodin, Michael (Ferchau; ADITG/ESM1)
2020-02-26 16:40 ` Jacopo Mondi
2020-03-04 20:02 ` niklas.soderlund
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1582026251-21047-1-git-send-email-mrodin@de.adit-jv.com \
--to=mrodin@de.adit-jv.com \
--cc=akiyama@nds-osk.co.jp \
--cc=efriedrich@de.adit-jv.com \
--cc=erosca@de.adit-jv.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-renesas-soc@vger.kernel.org \
--cc=mchehab@kernel.org \
--cc=niklas.soderlund@ragnatech.se \
--cc=p.zabel@pengutronix.de \
--cc=sudipi@jp.adit-jv.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).