[PATCH v2] mmc: dw_mmc: insmod followed by rmmod will hung for eMMC

Prabu Thangamuthu
2015-05-28T12:21:23Z

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>
---
Change log v2:
-Added prefix "mmc:" to the commit message header.
-Updated the Commit Message.

drivers/mmc/host/dw_mmc.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 55179f1..40e9d8e 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -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);
--
1.7.6.5