On 7/11/20 1:41 PM, 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: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
> ---
>
> 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'
>
> drivers/hwmon/drivetemp.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/hwmon/drivetemp.c b/drivers/hwmon/drivetemp.c
> index 0d4f3d97ffc6..da9cfcbecc96 100644
> --- a/drivers/hwmon/drivetemp.c
> +++ b/drivers/hwmon/drivetemp.c
> @@ -285,6 +285,36 @@ 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 was actually caught exhibiting the problem
> + * let's play safe here to avoid data corruption and ban the whole family.
> + */
> + "TOSHIBA DT01ACA0",
> + "TOSHIBA DT01ACA1",
> + "TOSHIBA DT01ACA2",
> + "TOSHIBA DT01ACA3",
> +};
> +
> +static bool drivetemp_sct_avoid(struct drivetemp_data *st)
> +{
> + struct scsi_device *sdev = st->sdev;
> + unsigned int ctr;
> +
> + if (!sdev->model)
> + return false;
> +
> + for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
> + if (strncmp(sdev->model, sct_avoid_models[ctr], 16) == 0)
Why strncmp, and why length 16 ? Both strings are, as far as I can see,
0 terminated. A fixed length only asks for trouble later on as more models
are added to the list.
Also, please use "!" instead of "== 0".
> + return true;
> +
> + return false;
> +}
> +
> static int drivetemp_identify_sata(struct drivetemp_data *st)
> {
> struct scsi_device *sdev = st->sdev;
> @@ -326,6 +356,13 @@ 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;
>
>
