mmc: cqhci: Fix task clearing in CQE error recovery
authorAdrian Hunter <adrian.hunter@intel.com>
Fri, 3 Nov 2023 08:47:20 +0000 (10:47 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 8 Dec 2023 07:51:13 +0000 (08:51 +0100)
commit3a9a9c256f0245775533ebc07a8613eaa7ce28fe
tree5d8fc1d8c08f61c4869e253c79ec1491216a30c8
parentdef67fd8efde7f239559f24da87f1ee61223be2a
mmc: cqhci: Fix task clearing in CQE error recovery

commit 1de1b77982e1a1df9707cb11f9b1789e6b8919d4 upstream.

If a task completion notification (TCN) is received when there is no
outstanding task, the cqhci driver issues a "spurious TCN" warning. This
was observed to happen right after CQE error recovery.

When an error interrupt is received the driver runs recovery logic.
It halts the controller, clears all pending tasks, and then re-enables
it. On some platforms, like Intel Jasper Lake, a stale task completion
event was observed, regardless of the CQHCI_CLEAR_ALL_TASKS bit being set.

This results in either:
a) Spurious TC completion event for an empty slot.
b) Corrupted data being passed up the stack, as a result of premature
   completion for a newly added task.

Rather than add a quirk for affected controllers, ensure tasks are cleared
by toggling CQHCI_ENABLE, which would happen anyway if
cqhci_clear_all_tasks() timed out. This is simpler and should be safe and
effective for all controllers.

Fixes: a4080225f51d ("mmc: cqhci: support for command queue enabled host")
Cc: stable@vger.kernel.org
Reported-by: Kornel Dulęba <korneld@chromium.org>
Tested-by: Kornel Dulęba <korneld@chromium.org>
Co-developed-by: Kornel Dulęba <korneld@chromium.org>
Signed-off-by: Kornel Dulęba <korneld@chromium.org>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20231103084720.6886-7-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/mmc/host/cqhci-core.c