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From: Stephen Boyd <swboyd@chromium.org>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
	Wolfram Sang <wsa@the-dreams.de>
Subject: [PATCH] Input: elants_i2c - Use DMA safe i2c when possible
Date: Wed, 10 Oct 2018 09:55:17 -0700	[thread overview]
Message-ID: <20181010165517.178545-1-swboyd@chromium.org> (raw)

This irq handler is always reading bytes from the device into a
kmalloced buffer, so it's safe to mark this transaction as DMA safe.
This avoids bouncing the buffer when an i2c controller decides to use
DMA for a transaction.

Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 drivers/input/touchscreen/elants_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index d21ca39b0fdb..be44abb8de33 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -863,7 +863,7 @@ static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 	int i;
 	int len;
 
-	len = i2c_master_recv(client, ts->buf, sizeof(ts->buf));
+	len = i2c_master_recv_dmasafe(client, ts->buf, sizeof(ts->buf));
 	if (len < 0) {
 		dev_err(&client->dev, "%s: failed to read data: %d\n",
 			__func__, len);
-- 
Sent by a computer through tubes

             reply	other threads:[~2018-10-10 16:55 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10 16:55 Stephen Boyd [this message]
2018-10-10 17:07 ` [PATCH] Input: elants_i2c - Use DMA safe i2c when possible Dmitry Torokhov

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