From: Michael Walle <michael@walle.cc>
To: "Codrin Ciubotariu" <codrin.ciubotariu@microchip.com>,
"Nicolas Ferre" <nicolas.ferre@microchip.com>,
"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
"Claudiu Beznea" <claudiu.beznea@microchip.com>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
"Christian König" <christian.koenig@amd.com>
Cc: linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
Michael Walle <michael@walle.cc>,
stable@vger.kernel.org
Subject: [PATCH] i2c: at91: use dma safe buffers
Date: Thu, 3 Mar 2022 17:17:24 +0100 [thread overview]
Message-ID: <20220303161724.3324948-1-michael@walle.cc> (raw)
The supplied buffer might be on the stack and we get the following error
message:
[ 3.312058] at91_i2c e0070600.i2c: rejecting DMA map of vmalloc memory
Use i2c_{get,put}_dma_safe_msg_buf() to get a DMA-able memory region if
necessary.
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle <michael@walle.cc>
---
I'm not sure if or which Fixes: tag I should add to this patch. The issue
seems to be since a very long time, but nobody seem to have triggered it.
FWIW, I'm using the sff,sfp driver, which triggers this.
drivers/i2c/busses/i2c-at91-master.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index b0eae94909f4..a7a22fedbaba 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -656,6 +656,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
unsigned int_addr_flag = 0;
struct i2c_msg *m_start = msg;
bool is_read;
+ u8 *dma_buf;
dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
@@ -703,7 +704,18 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
dev->msg = m_start;
dev->recv_len_abort = false;
+ if (dev->use_dma) {
+ dma_buf = i2c_get_dma_safe_msg_buf(m_start, 1);
+ if (!dma_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ dev->buf = dma_buf;
+ }
+
+
ret = at91_do_twi_transfer(dev);
+ i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
ret = (ret < 0) ? ret : num;
out:
--
2.30.2
next reply other threads:[~2022-03-03 16:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-03 16:17 Michael Walle [this message]
2022-03-04 7:35 ` [PATCH] i2c: at91: use dma safe buffers Christian König
2022-03-04 8:04 ` Wolfram Sang
2022-03-04 8:10 ` Christian König
2022-03-04 8:43 ` Wolfram Sang
2022-03-04 8:54 ` Christian König
2022-03-28 7:35 ` Michael Walle
2022-04-05 9:23 ` Codrin.Ciubotariu
2022-04-05 9:38 ` Michael Walle
2022-04-05 10:02 ` Codrin.Ciubotariu
2022-04-05 11:09 ` Michael Walle
2022-04-05 13:58 ` Codrin.Ciubotariu
2022-04-05 14:08 ` Michael Walle
2022-04-07 11:50 ` Codrin.Ciubotariu
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