linux-kernel - [PATCH v2] mmc: pxamci: fix the device-tree probe deferral path

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Date:	Sat,  6 Feb 2016 22:14:54 +0100
From:	Robert Jarzmik <robert.jarzmik@...e.fr>
To:	Ulf Hansson <ulf.hansson@...aro.org>
Cc:	linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
	Robert Jarzmik <robert.jarzmik@...e.fr>
Subject: [PATCH v2] mmc: pxamci: fix the device-tree probe deferral path

When the gpio driver is probed after the mmc one, the read/write gpio
and card detection one return -EPROBE_DEFER. Unfortunately, the memory
region remains requested, and upon the next probe, the probe will fail
anyway with -EBUSY.

Fix this by releasing the memory resource upon probe failure.

More broadly, this patch uses devm_*() primitives whenever possible in
the probe function.

Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
---
Since v1: broaden the devm_*() enveloppe
---
 drivers/mmc/host/pxamci.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c
index 28a057fae0a1..a672b9259d34 100644
--- a/drivers/mmc/host/pxamci.c
+++ b/drivers/mmc/host/pxamci.c
@@ -654,12 +654,8 @@ static int pxamci_probe(struct platform_device *pdev)
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	irq = platform_get_irq(pdev, 0);
-	if (!r || irq < 0)
-		return -ENXIO;
-
-	r = request_mem_region(r->start, SZ_4K, DRIVER_NAME);
-	if (!r)
-		return -EBUSY;
+	if (irq < 0)
+		return irq;
 
 	mmc = mmc_alloc_host(sizeof(struct pxamci_host), &pdev->dev);
 	if (!mmc) {
@@ -727,9 +723,9 @@ static int pxamci_probe(struct platform_device *pdev)
 	host->irq = irq;
 	host->imask = MMC_I_MASK_ALL;
 
-	host->base = ioremap(r->start, SZ_4K);
-	if (!host->base) {
-		ret = -ENOMEM;
+	host->base = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(host->base)) {
+		ret = PTR_ERR(host->base);
 		goto out;
 	}
 
@@ -742,7 +738,8 @@ static int pxamci_probe(struct platform_device *pdev)
 	writel(64, host->base + MMC_RESTO);
 	writel(host->imask, host->base + MMC_I_MASK);
 
-	ret = request_irq(host->irq, pxamci_irq, 0, DRIVER_NAME, host);
+	ret = devm_request_irq(&pdev->dev, host->irq, pxamci_irq, 0,
+			       DRIVER_NAME, host);
 	if (ret)
 		goto out;
 
@@ -833,14 +830,11 @@ out:
 			dma_release_channel(host->dma_chan_rx);
 		if (host->dma_chan_tx)
 			dma_release_channel(host->dma_chan_tx);
-		if (host->base)
-			iounmap(host->base);
 		if (host->clk)
 			clk_put(host->clk);
 	}
 	if (mmc)
 		mmc_free_host(mmc);
-	release_resource(r);
 	return ret;
 }
 
@@ -870,17 +864,13 @@ static int pxamci_remove(struct platform_device *pdev)
 		       END_CMD_RES|PRG_DONE|DATA_TRAN_DONE,
 		       host->base + MMC_I_MASK);
 
-		free_irq(host->irq, host);
 		dmaengine_terminate_all(host->dma_chan_rx);
 		dmaengine_terminate_all(host->dma_chan_tx);
 		dma_release_channel(host->dma_chan_rx);
 		dma_release_channel(host->dma_chan_tx);
-		iounmap(host->base);
 
 		clk_put(host->clk);
 
-		release_resource(host->res);
-
 		mmc_free_host(mmc);
 	}
 	return 0;
-- 
2.1.4