On Sat, Jul 18, 2020 at 02:32:10PM +0200, Maciej S. Szmigiero wrote:
> It has been observed that Toshiba DT01ACA family drives have
> WRITE FPDMA QUEUED command timeouts and sometimes just freeze until
> power-cycled under heavy write loads when their temperature is getting
> polled in SCT mode. The SMART mode seems to be fine, though.
>
> Let's make sure we don't use SCT mode for these drives then.
>
> While only the 3 TB model was actually caught exhibiting the problem let's
> play safe here to avoid data corruption and extend the ban to the whole
> family.
>
> Fixes: 5b46903d8bf3 ("hwmon: Driver for disk and solid state drives with
> temperature sensors")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Maciej S. Szmigiero <m...@maciej.szmigiero.name>
Applied.
Thanks,
Guenter
> ---
>
> Notes:
> This behavior was observed on two different DT01ACA3 drives.
>
> Usually, a series of queued WRITE FPDMA QUEUED commands just time out,
> but sometimes the whole drive freezes. Merely disconnecting and
> reconnecting SATA interface cable then does not unfreeze the drive.
>
> One has to disconnect and reconnect the drive power connector for the
> drive to be detected again (suggesting the drive firmware itself has
> crashed).
>
> This only happens when the drive temperature is polled very often (like
> every second), so occasional SCT usage via smartmontools is probably
> safe.
>
> Changes from v1:
> 'SCT blacklist' -> 'SCT avoid models'
>
> Changes from v2:
> * Switch to prefix matching and use it to match the DT01ACAx family,
>
> * Use "!" instead of "== 0",
>
> * Add a comment about the contents of the "model" field.
>
> drivers/hwmon/drivetemp.c | 43 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 43 insertions(+)
>
> diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
> index 0d4f3d97ffc6..72c760373957 100644
> --- a/drivers/hwmon/drivetemp.c
> +++ b/drivers/hwmon/drivetemp.c
> @@ -285,6 +285,42 @@ static int drivetemp_get_scttemp(struct drivetemp_data
> *st, u32 attr, long *val)
> return err;
> }
>
> +static const char * const sct_avoid_models[] = {
> +/*
> + * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes
> just
> + * freeze until power-cycled under heavy write loads when their temperature
> is
> + * getting polled in SCT mode. The SMART mode seems to be fine, though.
> + *
> + * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the
> + * problem let's play safe here to avoid data corruption and ban the whole
> + * DT01ACAx family.
> +
> + * The models from this array are prefix-matched.
> + */
> + "TOSHIBA DT01ACA",
> +};
> +
> +static bool drivetemp_sct_avoid(struct drivetemp_data *st)
> +{
> + struct scsi_device *sdev = st->sdev;
> + unsigned int ctr;
> +
> + if (!sdev->model)
> + return false;
> +
> + /*
> + * The "model" field contains just the raw SCSI INQUIRY response
> + * "product identification" field, which has a width of 16 bytes.
> + * This field is space-filled, but is NOT NULL-terminated.
> + */
> + for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
> + if (!strncmp(sdev->model, sct_avoid_models[ctr],
> + strlen(sct_avoid_models[ctr])))
> + return true;
> +
> + return false;
> +}
> +
> static int drivetemp_identify_sata(struct drivetemp_data *st)
> {
> struct scsi_device *sdev = st->sdev;
> @@ -326,6 +362,13 @@ static int drivetemp_identify_sata(struct drivetemp_data
> *st)
> /* bail out if this is not a SATA device */
> if (!is_ata || !is_sata)
> return -ENODEV;
> +
> + if (have_sct && drivetemp_sct_avoid(st)) {
> + dev_notice(&sdev->sdev_gendev,
> + "will avoid using SCT for temperature monitoring\n");
> + have_sct = false;
> + }
> +
> if (!have_sct)
> goto skip_sct;
>
