All of lore.kernel.org
 help / color / mirror / Atom feed
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Mark Brown <broonie@kernel.org>
Cc: <linux-spi@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	Mason Yang <masonccyang@mxic.com.tw>,
	Julien Su <juliensu@mxic.com.tw>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	stable@vger.kernel.org
Subject: [PATCH 1/4] spi: mxic: Fix transmit path
Date: Thu, 19 Sep 2019 22:25:01 +0200	[thread overview]
Message-ID: <20190919202504.9619-1-miquel.raynal@bootlin.com> (raw)

In certain circumstances, it is needed to check INT_TX_EMPTY and
INT_RX_NOT_EMPTY in the transmit path, not only in the receive
path. In both cases, the delay penalty is negligible.

Fixes: b942d80b0a39 ("spi: Add MXIC controller driver")
Cc: stable@vger.kernel.org
Suggested-by: Mason Yang <masonccyang@mxic.com.tw>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/spi/spi-mxic.c | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index f48563c09b97..eaa7a6a9044d 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -304,25 +304,21 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 
 		writel(data, mxic->regs + TXD(nbytes % 4));
 
+		ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+					 sts & INT_TX_EMPTY, 0, USEC_PER_SEC);
+		if (ret)
+			return ret;
+
+		ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+					 sts & INT_RX_NOT_EMPTY, 0,
+					 USEC_PER_SEC);
+		if (ret)
+			return ret;
+
+		data = readl(mxic->regs + RXD);
 		if (rxbuf) {
-			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-						 sts & INT_TX_EMPTY, 0,
-						 USEC_PER_SEC);
-			if (ret)
-				return ret;
-
-			ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-						 sts & INT_RX_NOT_EMPTY, 0,
-						 USEC_PER_SEC);
-			if (ret)
-				return ret;
-
-			data = readl(mxic->regs + RXD);
 			data >>= (8 * (4 - nbytes));
 			memcpy(rxbuf + pos, &data, nbytes);
-			WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
-		} else {
-			readl(mxic->regs + RXD);
 		}
 		WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
 
-- 
2.20.1


             reply	other threads:[~2019-09-19 20:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-19 20:25 Miquel Raynal [this message]
2019-09-20 11:02 ` [PATCH 1/4] spi: mxic: Fix transmit path Mark Brown
2019-09-20 11:02   ` Mark Brown

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=20190919202504.9619-1-miquel.raynal@bootlin.com \
    --to=miquel.raynal@bootlin.com \
    --cc=boris.brezillon@collabora.com \
    --cc=broonie@kernel.org \
    --cc=juliensu@mxic.com.tw \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=masonccyang@mxic.com.tw \
    --cc=stable@vger.kernel.org \
    --cc=thomas.petazzoni@bootlin.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.