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Commit 1de1b779 authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
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mmc: cqhci: Fix task clearing in CQE error recovery

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: a4080225

 ("mmc: cqhci: support for command queue enabled host")
Cc: stable@vger.kernel.org
Reported-by: default avatarKornel Dulęba <korneld@chromium.org>
Tested-by: default avatarKornel Dulęba <korneld@chromium.org>
Co-developed-by: default avatarKornel Dulęba <korneld@chromium.org>
Signed-off-by: default avatarKornel Dulęba <korneld@chromium.org>
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarAvri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20231103084720.6886-7-adrian.hunter@intel.com
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 35597bdb
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