[PATCH 1/1] dw_mmc: insmod followed by rmmod will hung for eMMC

From: Prabu Thangamuthu
Date: Mon May 18 2015 - 10:23:31 EST


Removing dw_mmc driver immediately after inserting the dw_mmc driver is
getting hung for eMMC device. Root cause for this issue is, dw_mci_remove
will disable all the interrupts then it will call dw_mci_cleanup_slot.
dw_mci_cleanup_slot is issuing CMD6 to disable boot partition access and
it's 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@xxxxxxxxxxxx>
---
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 5f5adaf..f0a0aff 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -2941,15 +2941,15 @@ 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
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