[PATCH 5.8 21/85] memstick: Skip allocating card when removing host

From: Greg Kroah-Hartman
Date: Mon Oct 05 2020 - 11:31:57 EST


From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

commit 62c59a8786e6bb75569cee91dab66e9da3ff4b68 upstream.

After commit 6827ca573c03 ("memstick: rtsx_usb_ms: Support runtime power
management"), removing module rtsx_usb_ms will be stuck.

The deadlock is caused by powering on and powering off at the same time,
the former one is when memstick_check() is flushed, and the later is called
by memstick_remove_host().

Soe let's skip allocating card to prevent this issue.

Fixes: 6827ca573c03 ("memstick: rtsx_usb_ms: Support runtime power management")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200925084952.13220-1-kai.heng.feng@xxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/memstick/core/memstick.c | 4 ++++
include/linux/memstick.h | 1 +
2 files changed, 5 insertions(+)

--- a/drivers/memstick/core/memstick.c
+++ b/drivers/memstick/core/memstick.c
@@ -441,6 +441,9 @@ static void memstick_check(struct work_s
} else if (host->card->stop)
host->card->stop(host->card);

+ if (host->removing)
+ goto out_power_off;
+
card = memstick_alloc_card(host);

if (!card) {
@@ -545,6 +548,7 @@ EXPORT_SYMBOL(memstick_add_host);
*/
void memstick_remove_host(struct memstick_host *host)
{
+ host->removing = 1;
flush_workqueue(workqueue);
mutex_lock(&host->lock);
if (host->card)
--- a/include/linux/memstick.h
+++ b/include/linux/memstick.h
@@ -281,6 +281,7 @@ struct memstick_host {

struct memstick_dev *card;
unsigned int retries;
+ bool removing;

/* Notify the host that some requests are pending. */
void (*request)(struct memstick_host *host);