linux-kernel - [PATCH 1/2] i2c: stm32: fix error message on upon dma_request

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Message-ID: <1600080034-2050-2-git-send-email-alain.volmat@st.com>
Date:   Mon, 14 Sep 2020 12:40:33 +0200
From:   Alain Volmat <alain.volmat@...com>
To:     <wsa@...nel.org>, <pierre-yves.mordret@...com>
CC:     <alexandre.torgue@...com>, <linux-i2c@...r.kernel.org>,
        <linux-stm32@...md-mailman.stormreply.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <fabrice.gasnier@...com>,
        <krzk@...nel.org>, <h.assmann@...gutronix.de>,
        <alain.volmat@...com>
Subject: [PATCH 1/2] i2c: stm32: fix error message on upon dma_request_chan & defer handling

DMA usage is optional for the I2C driver. check for the -ENODEV
error in order to avoid displaying an error when no DMA
has been requested.
Cleaning up the error messages during probe, remove the additional
-EPROBE_DEFER within probe function since additional error message
doesn't give much more information than what is already reported
within the stm32_i2c_dma_request function.

CC: Krzysztof Kozlowski <krzk@...nel.org>
CC: Holger Assmann <h.assmann@...gutronix.de>
Signed-off-by: Alain Volmat <alain.volmat@...com>
---
This patch replaces the patch [i2c: stm32: do not display error when DMA is not requested]
previously sent on the mailing list.
---
 drivers/i2c/busses/i2c-stm32.c   |  6 ++----
 drivers/i2c/busses/i2c-stm32f7.c | 13 ++++++-------
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c
index 3f69a3bb6119..468620db9ea5 100644
--- a/drivers/i2c/busses/i2c-stm32.c
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -26,7 +26,7 @@ struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
 	dma->chan_tx = dma_request_chan(dev, "tx");
 	if (IS_ERR(dma->chan_tx)) {
 		ret = PTR_ERR(dma->chan_tx);
-		if (ret != -EPROBE_DEFER)
+		if ((ret != -ENODEV) && (ret != -EPROBE_DEFER))
 			dev_err(dev, "can't request DMA tx channel\n");
 		goto fail_al;
 	}
@@ -46,7 +46,7 @@ struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
 	dma->chan_rx = dma_request_chan(dev, "rx");
 	if (IS_ERR(dma->chan_rx)) {
 		ret = PTR_ERR(dma->chan_rx);
-		if (ret != -EPROBE_DEFER)
+		if ((ret != -ENODEV) && (ret != -EPROBE_DEFER))
 			dev_err(dev, "can't request DMA rx channel\n");
 
 		goto fail_tx;
@@ -76,8 +76,6 @@ struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
 	dma_release_channel(dma->chan_tx);
 fail_al:
 	devm_kfree(dev, dma);
-	if (ret != -EPROBE_DEFER)
-		dev_info(dev, "can't use DMA\n");
 
 	return ERR_PTR(ret);
 }
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index bff3479fe122..8a61320a9cb9 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -2052,14 +2052,13 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 	i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
 					     STM32F7_I2C_TXDR,
 					     STM32F7_I2C_RXDR);
-	if (PTR_ERR(i2c_dev->dma) == -ENODEV)
-		i2c_dev->dma = NULL;
-	else if (IS_ERR(i2c_dev->dma)) {
+	if (IS_ERR(i2c_dev->dma)) {
 		ret = PTR_ERR(i2c_dev->dma);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev,
-				"Failed to request dma error %i\n", ret);
-		goto fmp_clear;
+		/* DMA support is optional, only report other errors */
+		if (ret != -ENODEV)
+			goto fmp_clear;
+		dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n");
+		i2c_dev->dma = NULL;
 	}
 
 	if (i2c_dev->wakeup_src) {
-- 
2.7.4