asix-sigma: Only change number of channels after successful firmware upload

The asix-sigma driver supports different samplerates, which will involve
different firmware images and will affect the number of available logic
channels as well as their memory layout in downloaded sample data.

Make sure to only store the configuration's parameters after the setup
of that configuration has successfully completed, and make sure to store
a consistent set of parameters. Specifically don't change the number of
channels when the firmware upload failed.

This fixes part of bug #471.

Suggested-By: Marian Cingel <redacted>

diff --git a/src/hardware/asix-sigma/protocol.c b/src/hardware/asix-sigma/protocol.c
index a81ec2f62f05344c877488ea1deeb9ebcc752cda..ee7ce02211e373dbc55f13d82ac3d50ca77deefc 100644 (file)
--- a/src/hardware/asix-sigma/protocol.c
+++ b/src/hardware/asix-sigma/protocol.c
@@ -554,6 +554,7 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t sampler
        struct drv_context *drvc;
        size_t i;
        int ret;
+       int num_channels;
 
        devc = sdi->priv;
        drvc = sdi->driver->context;
@@ -572,15 +573,16 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t sampler
         * firmware is required and higher rates might limit the set
         * of available channels.
         */
+       num_channels = devc->num_channels;
        if (samplerate <= SR_MHZ(50)) {
                ret = upload_firmware(drvc->sr_ctx, 0, devc);
-               devc->num_channels = 16;
+               num_channels = 16;
        } else if (samplerate == SR_MHZ(100)) {
                ret = upload_firmware(drvc->sr_ctx, 1, devc);
-               devc->num_channels = 8;
+               num_channels = 8;
        } else if (samplerate == SR_MHZ(200)) {
                ret = upload_firmware(drvc->sr_ctx, 2, devc);
-               devc->num_channels = 4;
+               num_channels = 4;
        }
 
        /*
@@ -589,6 +591,7 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t sampler
         * an "event" (memory organization internal to the device).
         */
        if (ret == SR_OK) {
+               devc->num_channels = num_channels;
                devc->cur_samplerate = samplerate;
                devc->samples_per_event = 16 / devc->num_channels;
                devc->state.state = SIGMA_IDLE;