From 8d27c2186eeac351c08022e3580f1348fe09d7b5 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Thu, 7 Apr 2022 17:08:28 +0200 Subject: [PATCH] i2c: at91: use dma safe buffers [ Upstream commit 03fbb903c8bf7e53e101e8d9a7b261264317c411 ] 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. Fixes: 60937b2cdbf9 ("i2c: at91: add dma support") Signed-off-by: Michael Walle Reviewed-by: Codrin Ciubotariu Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-at91-master.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index b0eae94..5eca3b3 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 +704,17 @@ 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: -- 2.7.4