Commit 048fd7e6 authored May 28, 2015 by Prabu Thangamuthu Committed by Ulf Hansson Jun 12, 2015

mmc: dw_mmc: insmod followed by rmmod will hung for eMMC



Remove module of dw_mmc driver will hung for eMMC devices if we follow the
steps which are listed below,
	insmod dw_mmc.ko
	insmod dw_mmc-pci.ko
	rmmod dw_mmc-pci.ko

The root cause for this issue is, dw_mci_remove() will disable all the
interrupts by programming 0x0 to INTMASK register then it will call
dw_mci_cleanup_slot(). But dw_mci_cleanup_slot() is issuing CMD6 to
disable the eMMC boot partition and it is waiting for Command Complete
interrupt. Since INTMASK was already cleared by dw_mci_remove(), Command
Complete interrupt is not reaching the system. This leads to process hung.

Signed-off-by: Prabu Thangamuthu <prabu.t@synopsys.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

parent 5fd26c7e

drivers/mmc/host/dw_mmc.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2926,15 +2926,15 @@ void dw_mci_remove(struct dw_mci *host)
		{
		int i;

		mci_writel(host, RINTSTS, 0xFFFFFFFF);
		mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

		for (i = 0; i < host->num_slots; i++) {
		dev_dbg(host->dev, "remove slot %d\n", i);
		if (host->slot[i])
		dw_mci_cleanup_slot(host->slot[i], i);
		}

		mci_writel(host, RINTSTS, 0xFFFFFFFF);
		mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

		/* disable clock to CIU */
		mci_writel(host, CLKENA, 0);
		mci_writel(host, CLKSRC, 0);

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