[PATCH 4.20 076/127] mmc: atmel-mci: do not assume idle after atmci_request_end

From: Greg Kroah-Hartman
Date: Thu Jan 24 2019 - 14:44:10 EST


4.20-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit ae460c115b7aa50c9a36cf78fced07b27962c9d0 ]

On our AT91SAM9260 board we use the same sdio bus for wifi and for the
sd card slot. This caused the atmel-mci to give the following splat on
the serial console:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 538 at drivers/mmc/host/atmel-mci.c:859 atmci_send_command+0x24/0x44
Modules linked in:
CPU: 0 PID: 538 Comm: mmcqd/0 Not tainted 4.14.76 #14
Hardware name: Atmel AT91SAM9
[<c000fccc>] (unwind_backtrace) from [<c000d3dc>] (show_stack+0x10/0x14)
[<c000d3dc>] (show_stack) from [<c0017644>] (__warn+0xd8/0xf4)
[<c0017644>] (__warn) from [<c0017704>] (warn_slowpath_null+0x1c/0x24)
[<c0017704>] (warn_slowpath_null) from [<c033bb9c>] (atmci_send_command+0x24/0x44)
[<c033bb9c>] (atmci_send_command) from [<c033e984>] (atmci_start_request+0x1f4/0x2dc)
[<c033e984>] (atmci_start_request) from [<c033f3b4>] (atmci_request+0xf0/0x164)
[<c033f3b4>] (atmci_request) from [<c0327108>] (mmc_start_request+0x280/0x2d0)
[<c0327108>] (mmc_start_request) from [<c032800c>] (mmc_start_areq+0x230/0x330)
[<c032800c>] (mmc_start_areq) from [<c03366f8>] (mmc_blk_issue_rw_rq+0xc4/0x310)
[<c03366f8>] (mmc_blk_issue_rw_rq) from [<c03372c4>] (mmc_blk_issue_rq+0x118/0x5ac)
[<c03372c4>] (mmc_blk_issue_rq) from [<c033781c>] (mmc_queue_thread+0xc4/0x118)
[<c033781c>] (mmc_queue_thread) from [<c002daf8>] (kthread+0x100/0x118)
[<c002daf8>] (kthread) from [<c000a580>] (ret_from_fork+0x14/0x34)
---[ end trace 594371ddfa284bd6 ]---

This is:
WARN_ON(host->cmd);

This was fixed on our board by letting atmci_request_end determine what
state we are in. Instead of unconditionally setting it to STATE_IDLE on
STATE_END_REQUEST.

Signed-off-by: Jonas Danielsson <jonas@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/mmc/host/atmel-mci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index be53044086c7..fbc56ee99682 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1954,13 +1954,14 @@ static void atmci_tasklet_func(unsigned long priv)
}

atmci_request_end(host, host->mrq);
- state = STATE_IDLE;
+ goto unlock; /* atmci_request_end() sets host->state */
break;
}
} while (state != prev_state);

host->state = state;

+unlock:
spin_unlock(&host->lock);
}

--
2.19.1