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 07:52:16 +0000 (08:52 +0100)
commitc7cf5f0bfd9ed73971ac4b5463af2d3f1d78e231
tree1ba4565eb377a1c1598927620f85c8910c0cf034
parent25b14a7eecfbc57b953825bdd67f88aa902dd15e
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