openwrt/target/linux/s3c24xx/patches/0251-My-GTA01-2.6.26-kernel-was-crashing-within-mmc_power.patch

From 0733a2e1b598dec898fef5066b737764170aaf62 Mon Sep 17 00:00:00 2001
From: Andy Green <agreen@pads.home.warmcat.com>
Date: Sun, 10 Aug 2008 09:27:16 +0100
Subject: [PATCH] My GTA01 2.6.26 kernel was crashing within mmc_power_up(), at the first
 call to mmc_set_ios(host), due to host->ops being NULL. mmc_power_up()
 was being called by mmc_rescan().

The only possible call path I can imagine for that is s3cmci_irq_cd
getting called before host->ops is set, thus calling mmc_detect_change()
which will schedule host->detect which is mmc_rescan.

This patch avoids the problem by moving the enable of the gpio_detect
interrupt to just before calling mmc_add_host(), where everything else
is already set up.

Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
---
 drivers/mmc/host/s3cmci.c |   34 +++++++++++++++++-----------------
 1 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
index 9ef4d5b..107847a 100644
--- a/drivers/mmc/host/s3cmci.c
+++ b/drivers/mmc/host/s3cmci.c
@@ -1226,17 +1226,6 @@ static int s3cmci_probe(struct platform_device *pdev, int is2440)
 
 	disable_irq(host->irq);
 
-	s3c2410_gpio_cfgpin(host->pdata->gpio_detect, S3C2410_GPIO_IRQ);
-	set_irq_type(host->irq_cd, IRQT_BOTHEDGE);
-
-	if (request_irq(host->irq_cd, s3cmci_irq_cd, 0, DRIVER_NAME, host)) {
-		dev_err(&pdev->dev,
-			"failed to request card detect interrupt.\n");
-
-		ret = -ENOENT;
-		goto probe_free_irq;
-	}
-
 	if (host->pdata->gpio_wprotect)
 		s3c2410_gpio_cfgpin(host->pdata->gpio_wprotect,
 				    S3C2410_GPIO_INPUT);
@@ -1244,7 +1233,7 @@ static int s3cmci_probe(struct platform_device *pdev, int is2440)
 	if (s3c2410_dma_request(host->dma, &s3cmci_dma_client, NULL)) {
 		dev_err(&pdev->dev, "unable to get DMA channel.\n");
 		ret = -EBUSY;
-		goto probe_free_irq_cd;
+		goto probe_free_irq;
 	}
 
 	host->clk = clk_get(&pdev->dev, "sdi");
@@ -1281,10 +1270,21 @@ static int s3cmci_probe(struct platform_device *pdev, int is2440)
 	    "irq_cd:%u dma:%u.\n", (host->is2440?"2440":""),
 	    host->base, host->irq, host->irq_cd, host->dma);
 
+	s3c2410_gpio_cfgpin(host->pdata->gpio_detect, S3C2410_GPIO_IRQ);
+	set_irq_type(host->irq_cd, IRQT_BOTHEDGE);
+
+	if (request_irq(host->irq_cd, s3cmci_irq_cd, 0, DRIVER_NAME, host)) {
+		dev_err(&pdev->dev,
+			"failed to request card detect interrupt.\n");
+
+		ret = -ENOENT;
+		goto probe_disable_clk;
+	}
+
 	ret = mmc_add_host(mmc);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to add mmc host.\n");
-		goto probe_disable_clk;
+		goto probe_free_irq_cd;
 	}
 
 	platform_set_drvdata(pdev, mmc);
@@ -1292,15 +1292,15 @@ static int s3cmci_probe(struct platform_device *pdev, int is2440)
 	dev_info(&pdev->dev, "initialisation done.\n");
 	return 0;
 
+ probe_free_irq_cd:
+	free_irq(host->irq_cd, host);
+
  probe_disable_clk:
 	clk_disable(host->clk);
 
  probe_free_clk:
 	clk_put(host->clk);
 
- probe_free_irq_cd:
-	free_irq(host->irq_cd, host);
- 
  probe_free_dma:
 	s3c2410_dma_free(host->dma, &s3cmci_dma_client);
 
@@ -1325,10 +1325,10 @@ static int s3cmci_remove(struct platform_device *pdev)
 	struct s3cmci_host 	*host = mmc_priv(mmc);
 
 	mmc_remove_host(mmc);
+	free_irq(host->irq_cd, host);
 	clk_disable(host->clk);
 	clk_put(host->clk);
 	s3c2410_dma_free(host->dma, &s3cmci_dma_client);
-	free_irq(host->irq_cd, host);
 	free_irq(host->irq, host);
 	iounmap(host->base);
 	release_mem_region(host->mem->start, RESSIZE(host->mem));
-- 
1.5.6.3