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| author | Dan Williams <dan.j.williams@intel.com> | 2019-02-13 09:04:07 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2019-02-20 14:18:59 -0800 |
| commit | 5479b2757f26fe9908fc341d105b2097fe820b6f (patch) | |
| tree | 8bf25b81a20115dcd9d417428af9ae414ab505c7 /drivers | |
| parent | e34b8252a3d2893ca55c82dbfcdaa302fa03d400 (diff) | |
| download | linux-stable-5479b2757f26fe9908fc341d105b2097fe820b6f.tar.gz linux-stable-5479b2757f26fe9908fc341d105b2097fe820b6f.tar.bz2 linux-stable-5479b2757f26fe9908fc341d105b2097fe820b6f.zip | |
nfit/ars: Allow root to busy-poll the ARS state machine
The ARS implementation implements exponential back-off on the poll
interval to prevent high-frequency access to the DIMM / platform
interface. Depending on when the ARS completes the poll interval may
exceed the completion event by minutes. Allow root to reset the timeout
each time it probes the status. A one-second timeout is still enforced,
but root can otherwise can control the poll interval.
Fixes: bc6ba8085842 ("nfit, address-range-scrub: rework and simplify ARS...")
Cc: <stable@vger.kernel.org>
Reported-by: Erwin Tsaur <erwin.tsaur@oracle.com>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/nfit/core.c | 8 | ||||
| -rw-r--r-- | drivers/acpi/nfit/nfit.h | 1 |
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 90312892093e..629cf91649d2 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1333,6 +1333,13 @@ static ssize_t scrub_show(struct device *dev, busy = test_bit(ARS_BUSY, &acpi_desc->scrub_flags) && !test_bit(ARS_CANCEL, &acpi_desc->scrub_flags); rc = sprintf(buf, "%d%s", acpi_desc->scrub_count, busy ? "+\n" : "\n"); + /* Allow an admin to poll the busy state at a higher rate */ + if (busy && capable(CAP_SYS_RAWIO) && !test_and_set_bit(ARS_POLL, + &acpi_desc->scrub_flags)) { + acpi_desc->scrub_tmo = 1; + mod_delayed_work(nfit_wq, &acpi_desc->dwork, HZ); + } + mutex_unlock(&acpi_desc->init_mutex); device_unlock(dev); return rc; @@ -3187,6 +3194,7 @@ static void acpi_nfit_scrub(struct work_struct *work) else notify_ars_done(acpi_desc); memset(acpi_desc->ars_status, 0, acpi_desc->max_ars); + clear_bit(ARS_POLL, &acpi_desc->scrub_flags); mutex_unlock(&acpi_desc->init_mutex); } diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index 897ce10192a0..d14bad687fb8 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -213,6 +213,7 @@ struct nfit_mem { enum scrub_flags { ARS_BUSY, ARS_CANCEL, + ARS_POLL, }; struct acpi_nfit_desc { |