On Tuesday 22 December 2020 16:44:05 CET Kalle Valo wrote: > Jerome Pouiller <Jerome.Pouiller@xxxxxxxxxx> writes: > > > +/* NOTE: wfx_send_pds() destroy buf */ > > +int wfx_send_pds(struct wfx_dev *wdev, u8 *buf, size_t len) > > +{ > > + int ret; > > + int start, brace_level, i; > > + > > + start = 0; > > + brace_level = 0; > > + if (buf[0] != '{') { > > + dev_err(wdev->dev, "valid PDS start with '{'. Did you forget to > > compress it?\n"); > > + return -EINVAL; > > + } > > + for (i = 1; i < len - 1; i++) { > > + if (buf[i] == '{') > > + brace_level++; > > + if (buf[i] == '}') > > + brace_level--; > > + if (buf[i] == '}' && !brace_level) { > > + i++; > > + if (i - start + 1 > WFX_PDS_MAX_SIZE) > > + return -EFBIG; > > + buf[start] = '{'; > > + buf[i] = 0; > > + dev_dbg(wdev->dev, "send PDS '%s}'\n", buf + start); > > + buf[i] = '}'; > > + ret = hif_configuration(wdev, buf + start, > > + i - start + 1); > > + if (ret > 0) { > > + dev_err(wdev->dev, "PDS bytes %d to %d: invalid data (unsupported > > options?)\n", > > + start, i); > > + return -EINVAL; > > + } > > + if (ret == -ETIMEDOUT) { > > + dev_err(wdev->dev, "PDS bytes %d to %d: chip didn't reply (corrupted > > file?)\n", > > + start, i); > > + return ret; > > + } > > + if (ret) { > > + dev_err(wdev->dev, "PDS bytes %d to %d: chip returned an unknown > > error\n", > > + start, i); > > + return -EIO; > > + } > > + buf[i] = ','; > > + start = i; > > + } > > + } > > + return 0; > > +} > > What does this function do? Looks very strange. I am going to add this comment: The device need data about the antenna configuration. This information in provided by PDS (Platform Data Set, this is the wording used in WF200 documentation) files. For hardware integrators, the full process to create PDS files is described here: https://github.com/SiliconLabs/wfx-firmware/blob/master/PDS/README.md So this function aims to send PDS to the device. However, the PDS file is often bigger than Rx buffers of the chip, so it has to be sent in multiple parts. In add, the PDS data cannot be split anywhere. The PDS files contains tree structures. Braces are used to enter/leave a level of the tree (in a JSON fashion). PDS files can only been split between root nodes. -- Jérôme Pouiller _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel