Add dev_warn_probe() and improve error handling in Rockchip SPI drivers

index e1ecd96c7858..81f2a966c124 100644
@@ -742,34 +742,32 @@ static int rockchip_spi_setup(struct spi_device *spi)
 
 static int rockchip_spi_probe(struct platform_device *pdev)
 {
-	int ret;
-	struct rockchip_spi *rs;
+	struct device_node *np = pdev->dev.of_node;
 	struct spi_controller *ctlr;
+	struct rockchip_spi *rs;
 	struct resource *mem;
-	struct device_node *np = pdev->dev.of_node;
 	u32 rsd_nsecs, num_cs;
 	bool target_mode;
+	int ret;
 
 	target_mode = of_property_read_bool(np, "spi-slave");
 
 	if (target_mode)
-		ctlr = spi_alloc_target(&pdev->dev,
-				sizeof(struct rockchip_spi));
+		ctlr = spi_alloc_target(&pdev->dev, sizeof(struct rockchip_spi));
 	else
-		ctlr = spi_alloc_host(&pdev->dev,
-				sizeof(struct rockchip_spi));
+		ctlr = spi_alloc_host(&pdev->dev, sizeof(struct rockchip_spi));
 
 	if (!ctlr)
 		return -ENOMEM;
 
 	platform_set_drvdata(pdev, ctlr);
 
 	rs = spi_controller_get_devdata(ctlr);
 
 	/* Get basic io resource and map it */
 	rs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
 	if (IS_ERR(rs->regs)) {
-		ret =  PTR_ERR(rs->regs);
+		ret = PTR_ERR(rs->regs);
 		goto err_put_ctlr;
 	}
 

@@ -794,26 +792,25 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 		goto err_put_ctlr;
 
 	ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
-			IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
+					IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
 	if (ret)
 		goto err_put_ctlr;
 
 	rs->dev = &pdev->dev;
 	rs->freq = clk_get_rate(rs->spiclk);
 
 	if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 				  &rsd_nsecs)) {
 		/* rx sample delay is expressed in parent clock cycles (max 3) */
-		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
-				1000000000 >> 8);
+		u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8), 1000000000 >> 8);
 		if (!rsd) {
 			dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
-					rs->freq, rsd_nsecs);
+				 rs->freq, rsd_nsecs);
 		} else if (rsd > CR0_RSD_MAX) {
 			rsd = CR0_RSD_MAX;
-			dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
-					rs->freq, rsd_nsecs,
-					CR0_RSD_MAX * 1000000000U / rs->freq);
+			dev_warn(rs->dev,
+				 "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
+				 rs->freq, rsd_nsecs, CR0_RSD_MAX * 1000000000U / rs->freq);
 		}
 		rs->rsd = rsd;
 	}

index 0d7fadcd4ed3..505d5089bf03 100644
@@ -591,19 +591,17 @@ static int rockchip_sfc_probe(struct platform_device *pdev)
 		return PTR_ERR(sfc->hclk);
 	}
 
-	sfc->use_dma = !of_property_read_bool(sfc->dev->of_node,
-					      "rockchip,sfc-no-dma");
+	sfc->use_dma = !of_property_read_bool(sfc->dev->of_node, "rockchip,sfc-no-dma");
 
 	if (sfc->use_dma) {
 		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
 		if (ret) {
 			dev_warn(dev, "Unable to set dma mask\n");
 			return ret;
 		}
 
 		sfc->buffer = dmam_alloc_coherent(dev, SFC_MAX_IOSIZE_VER3,
-						  &sfc->dma_buffer,
-						  GFP_KERNEL);
+						  &sfc->dma_buffer, GFP_KERNEL);
 		if (!sfc->buffer)
 			return -ENOMEM;
 	}

@@ -629,7 +627,6 @@ static int rockchip_sfc_probe(struct platform_device *pdev)
 			       0, pdev->name, sfc);
 	if (ret) {
 		dev_err(dev, "Failed to request irq\n");
-
 		goto err_irq;
 	}
 

index 505d5089bf03..7e0fb4944a34 100644
@@ -580,16 +580,14 @@ static int rockchip_sfc_probe(struct platform_device *pdev)
 		return PTR_ERR(sfc->regbase);
 
 	sfc->clk = devm_clk_get(&pdev->dev, "clk_sfc");
-	if (IS_ERR(sfc->clk)) {
-		dev_err(&pdev->dev, "Failed to get sfc interface clk\n");
-		return PTR_ERR(sfc->clk);
-	}
+	if (IS_ERR(sfc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(sfc->clk),
+				     "Failed to get sfc interface clk\n");
 
 	sfc->hclk = devm_clk_get(&pdev->dev, "hclk_sfc");
-	if (IS_ERR(sfc->hclk)) {
-		dev_err(&pdev->dev, "Failed to get sfc ahb clk\n");
-		return PTR_ERR(sfc->hclk);
-	}
+	if (IS_ERR(sfc->hclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(sfc->hclk),
+				     "Failed to get sfc ahb clk\n");
 
 	sfc->use_dma = !of_property_read_bool(sfc->dev->of_node, "rockchip,sfc-no-dma");
 

index 8c0733d3aad8..f2e41db0c09f 100644
@@ -4982,71 +4982,144 @@ define_dev_printk_level(_dev_info, KERN_INFO);
 
 #endif
 
+static void __dev_probe_failed(const struct device *dev, int err, bool fatal,
+			       const char *fmt, va_list vargsp)
+{
+	struct va_format vaf;
+	va_list vargs;
+
+	/*
+	 * On x86_64 and possibly on other architectures, va_list is actually a
+	 * size-1 array containing a structure.  As a result, function parameter
+	 * vargps decays from T[1] to T*, and &vargsp has type T** rather than
+	 * T(*)[1], which is expected by its assignment to vaf.va below.
+	 *
+	 * One standard way to solve this mess is by creating a copy in a local
+	 * variable of type va_list and then using a pointer to that local copy
+	 * instead, which is the approach employed here.
+	 */
+	va_copy(vargs, vargsp);
+
+	vaf.fmt = fmt;
+	vaf.va = &vargs;
+
+	switch (err) {
+	case -EPROBE_DEFER:
+		device_set_deferred_probe_reason(dev, &vaf);
+		dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
+		break;
+
+	case -ENOMEM:
+		/* Don't print anything on -ENOMEM, there's already enough output */
+		break;
+
+	default:
+		/* Log fatal final failures as errors, otherwise produce warnings */
+		if (fatal)
+			dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
+		else
+			dev_warn(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
+		break;
+	}
+
+	va_end(vargs);
+}
+
 /**
  * dev_err_probe - probe error check and log helper
  * @dev: the pointer to the struct device
  * @err: error value to test
  * @fmt: printf-style format string
  * @...: arguments as specified in the format string
  *
  * This helper implements common pattern present in probe functions for error
  * checking: print debug or error message depending if the error value is
  * -EPROBE_DEFER and propagate error upwards.
  * In case of -EPROBE_DEFER it sets also defer probe reason, which can be
  * checked later by reading devices_deferred debugfs attribute.
- * It replaces code sequence::
+ * It replaces the following code sequence::
  *
  * 	if (err != -EPROBE_DEFER)
  * 		dev_err(dev, ...);
  * 	else
  * 		dev_dbg(dev, ...);
  * 	return err;
  *
  * with::
  *
  * 	return dev_err_probe(dev, err, ...);
  *
- * Using this helper in your probe function is totally fine even if @err is
- * known to never be -EPROBE_DEFER.
+ * Using this helper in your probe function is totally fine even if @err
+ * is known to never be -EPROBE_DEFER.
  * The benefit compared to a normal dev_err() is the standardized format
- * of the error code, it being emitted symbolically (i.e. you get "EAGAIN"
- * instead of "-35") and the fact that the error code is returned which allows
- * more compact error paths.
+ * of the error code, which is emitted symbolically (i.e. you get "EAGAIN"
+ * instead of "-35"), and having the error code returned allows more
+ * compact error paths.
  *
  * Returns @err.
  */
 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
 {
-	struct va_format vaf;
-	va_list args;
+	va_list vargs;
 
-	va_start(args, fmt);
-	vaf.fmt = fmt;
-	vaf.va = &args;
+	va_start(vargs, fmt);
 
-	switch (err) {
-	case -EPROBE_DEFER:
-		device_set_deferred_probe_reason(dev, &vaf);
-		dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
-		break;
+	/* Use dev_err() for logging when err doesn't equal -EPROBE_DEFER */
+	__dev_probe_failed(dev, err, true, fmt, vargs);
 
-	case -ENOMEM:
-		/*
-		 * We don't print anything on -ENOMEM, there is already enough
-		 * output.
-		 */
-		break;
+	va_end(vargs);
 
-	default:
-		dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
-		break;
-	}
+	return err;
+}
+EXPORT_SYMBOL_GPL(dev_err_probe);
 
-	va_end(args);
+/**
+ * dev_warn_probe - probe error check and log helper
+ * @dev: the pointer to the struct device
+ * @err: error value to test
+ * @fmt: printf-style format string
+ * @...: arguments as specified in the format string
+ *
+ * This helper implements common pattern present in probe functions for error
+ * checking: print debug or warning message depending if the error value is
+ * -EPROBE_DEFER and propagate error upwards.
+ * In case of -EPROBE_DEFER it sets also defer probe reason, which can be
+ * checked later by reading devices_deferred debugfs attribute.
+ * It replaces the following code sequence::
+ *
+ * 	if (err != -EPROBE_DEFER)
+ * 		dev_warn(dev, ...);
+ * 	else
+ * 		dev_dbg(dev, ...);
+ * 	return err;
+ *
+ * with::
+ *
+ * 	return dev_warn_probe(dev, err, ...);
+ *
+ * Using this helper in your probe function is totally fine even if @err
+ * is known to never be -EPROBE_DEFER.
+ * The benefit compared to a normal dev_warn() is the standardized format
+ * of the error code, which is emitted symbolically (i.e. you get "EAGAIN"
+ * instead of "-35"), and having the error code returned allows more
+ * compact error paths.
+ *
+ * Returns @err.
+ */
+int dev_warn_probe(const struct device *dev, int err, const char *fmt, ...)
+{
+	va_list vargs;
+
+	va_start(vargs, fmt);
+
+	/* Use dev_warn() for logging when err doesn't equal -EPROBE_DEFER */
+	__dev_probe_failed(dev, err, false, fmt, vargs);
+
+	va_end(vargs);
 
 	return err;
 }
-EXPORT_SYMBOL_GPL(dev_err_probe);
+EXPORT_SYMBOL_GPL(dev_warn_probe);
 
 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
 {

index ca32b5bb28eb..eb2094e43050 100644
@@ -276,6 +276,7 @@ do {									\
 			dev_driver_string(dev), dev_name(dev), ## arg)
 
 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const char *fmt, ...);
+__printf(3, 4) int dev_warn_probe(const struct device *dev, int err, const char *fmt, ...);
 
 /* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */
 #define dev_err_ptr_probe(dev, ___err, fmt, ...) \

index 81f2a966c124..055cd6066466 100644
@@ -773,15 +773,15 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 
 	rs->apb_pclk = devm_clk_get_enabled(&pdev->dev, "apb_pclk");
 	if (IS_ERR(rs->apb_pclk)) {
-		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
-		ret = PTR_ERR(rs->apb_pclk);
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(rs->apb_pclk),
+				    "Failed to get apb_pclk\n");
 		goto err_put_ctlr;
 	}
 
 	rs->spiclk = devm_clk_get_enabled(&pdev->dev, "spiclk");
 	if (IS_ERR(rs->spiclk)) {
-		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
-		ret = PTR_ERR(rs->spiclk);
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(rs->spiclk),
+				    "Failed to get spi_pclk\n");
 		goto err_put_ctlr;
 	}
 

@@ -817,8 +817,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 
 	rs->fifo_len = get_fifo_len(rs);
 	if (!rs->fifo_len) {
-		dev_err(&pdev->dev, "Failed to get fifo length\n");
-		ret = -EINVAL;
+		ret = dev_err_probe(&pdev->dev, -EINVAL, "Failed to get fifo length\n");
 		goto err_put_ctlr;
 	}
 

@@ -858,22 +857,21 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 
 	ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
 	if (IS_ERR(ctlr->dma_tx)) {
-		/* Check tx to see if we need defer probing driver */
-		if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
-			ret = -EPROBE_DEFER;
+		/* Check tx to see if we need to defer driver probing */
+		ret = dev_warn_probe(rs->dev, PTR_ERR(ctlr->dma_tx),
+				     "Failed to request optional TX DMA channel\n");
+		if (ret == -EPROBE_DEFER)
 			goto err_disable_pm_runtime;
-		}
-		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 		ctlr->dma_tx = NULL;
 	}
 
 	ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
 	if (IS_ERR(ctlr->dma_rx)) {
-		if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
-			ret = -EPROBE_DEFER;
+		/* Check rx to see if we need to defer driver probing */
+		ret = dev_warn_probe(rs->dev, PTR_ERR(ctlr->dma_rx),
+				     "Failed to request optional RX DMA channel\n");
+		if (ret == -EPROBE_DEFER)
 			goto err_free_dma_tx;
-		}
-		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 		ctlr->dma_rx = NULL;
 	}