Currently, when a sensor value is read, the kernel calls OPAL, which in turn builds a message for the FSP, and waits for a message back.
The new device tree for OPAL sensors [1] adds new sensors that can be read synchronously (core temperatures for instance) and that don't need to wait for a response. This patch modifies the opal call to accept an OPAL_SUCCESS return value and cover the case above. [1] https://lists.ozlabs.org/pipermail/skiboot/2015-March/000639.html Signed-off-by: Cédric Le Goater <c...@fr.ibm.com> --- We still uselessly reserve a token (for the response) and take a lock, which might raise the need of a new 'opal_sensor_read_sync' call. arch/powerpc/platforms/powernv/opal-sensor.c | 29 +++++++++++++++++--------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal-sensor.c b/arch/powerpc/platforms/powernv/opal-sensor.c index 4ab67ef7abc9..99d6d9a371ab 100644 --- a/arch/powerpc/platforms/powernv/opal-sensor.c +++ b/arch/powerpc/platforms/powernv/opal-sensor.c @@ -46,18 +46,27 @@ int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data) mutex_lock(&opal_sensor_mutex); ret = opal_sensor_read(sensor_hndl, token, &data); - if (ret != OPAL_ASYNC_COMPLETION) - goto out_token; + switch (ret) { + case OPAL_ASYNC_COMPLETION: + ret = opal_async_wait_response(token, &msg); + if (ret) { + pr_err("%s: Failed to wait for the async response, %d\n", + __func__, ret); + goto out_token; + } - ret = opal_async_wait_response(token, &msg); - if (ret) { - pr_err("%s: Failed to wait for the async response, %d\n", - __func__, ret); - goto out_token; - } + ret = be64_to_cpu(msg.params[1]); + + *sensor_data = be32_to_cpu(data); + break; - *sensor_data = be32_to_cpu(data); - ret = be64_to_cpu(msg.params[1]); + case OPAL_SUCCESS: + *sensor_data = be32_to_cpu(data); + break; + + default: + break; + } out_token: mutex_unlock(&opal_sensor_mutex); -- 1.7.10.4 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
