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  1. 13 Sep, 2019 3 commits
    • Ulf Hansson's avatar
      mmc: tmio: Fixup runtime PM management during remove · 87b5d602
      Ulf Hansson authored 
      Accessing the device when it may be runtime suspended is a bug, which is
the case in tmio_mmc_host_remove(). Let's fix the behaviour.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      87b5d602
    • Ulf Hansson's avatar
      mmc: tmio: Fixup runtime PM management during probe · aa86f1a3
      Ulf Hansson authored 
      The tmio_mmc_host_probe() calls pm_runtime_set_active() to update the
runtime PM status of the device, as to make it reflect the current status
of the HW. This works fine for most cases, but unfortunate not for all.
Especially, there is a generic problem when the device has a genpd attached
and that genpd have the ->start|stop() callbacks assigned.

More precisely, if the driver calls pm_runtime_set_active() during
->probe(), genpd does not get to invoke the ->start() callback for it,
which means the HW isn't really fully powered on. Furthermore, in the next
phase, when the device becomes runtime suspended, genpd will invoke the
->stop() callback for it, potentially leading to usage count imbalance
problems, depending on what's implemented behind the callbacks of course.

To fix this problem, convert to call pm_runtime_get_sync() from
tmio_mmc_host_probe() rather than pm_runtime_set_active(). Additionally, to
avoid bumping usage counters and unnecessary re-initializing the HW the
first time the tmio driver's ->runtime_resume() callback is called,
introduce a state flag to keeping track of this.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      aa86f1a3
    • Ulf Hansson's avatar
      Revert "mmc: tmio: move runtime PM enablement to the driver implementations" · 8861474a
      Ulf Hansson authored 
      This reverts commit 7ff21319.

It turns out that the above commit introduces other problems. For example,
calling pm_runtime_set_active() must not be done prior calling
pm_runtime_enable() as that makes it fail. This leads to additional
problems, such as clock enables being wrongly balanced.

Rather than fixing the problem on top, let's start over by doing a revert.

Fixes: 7ff21319 ("mmc: tmio: move runtime PM enablement to the driver implementations")
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      8861474a
  3. 11 Sep, 2019 2 commits
  5. 08 Sep, 2019 4 commits
  7. 07 Sep, 2019 4 commits
  9. 06 Sep, 2019 17 commits
  11. 05 Sep, 2019 9 commits
  13. 04 Sep, 2019 1 commit
    • Al Viro's avatar
      configfs: provide exclusion between IO and removals · b0841eef
      Al Viro authored 
      Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      b0841eef
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