Laurent, Thank you for your comments. Please find my updates below. The updated patches will follow today.
-Manju On Thu, Apr 21, 2011 at 15:48:05, Laurent Pinchart wrote: > Hi Manjunath, > > On Wednesday 20 April 2011 17:30:08 Hadli, Manjunath wrote: > > Hi Laurent, > > Thank you for you very valuable and detailed comments. I have fixed a > > lot of your suggestions and there are a few questions I need more > > explanation for. I will send the fixed and updated patches as a > > follow-up after your clarifications. > > OK. Please see below for answsers. > > > On Thu, Apr 07, 2011 at 17:28:20, Laurent Pinchart wrote: > > > On Saturday 02 April 2011 11:40:49 Manjunath Hadli wrote: > > [snip] > > > > > +static u32 video2_numbuffers = 3; static u32 video3_numbuffers = > > > > +3; > > > > > > Why is the number of buffers set by a module parameter ? It should > > > be negotiated dynamically with REQBUFS. > > > > This is the minimum number of buffers to be allocated by the system as > > there is no scatter-gather mechanism in Davinci. To make sure of > > availability of a minimum numbers of buffers for the system which may > > not be available otherwise due to fragmentation, these are used. > > But you don't reserve the memory when the driver is probed, so how does this > help ? That was how it was done earlier. A detailed look at the code revealed that it is not applicable anymore. Fixed it. > > [snip] > > > > > + struct vpbe_display *disp_dev = (struct vpbe_display > > > > + *)disp_obj; > > > > + > > > > + /* Convert time represention from jiffies to timeval */ > > > > + jiffies_to_timeval(jiffies_time, &timevalue); > > > > > > Please use ktime_get_ts() or ktime_get_real_ts() to get the timestamp. > > > > Fixed. Used do_gettimeofday(). > > Please use ktime_get_ts() instead. It will return a monotonic clock timestamp. > Otherwise the buffer timestamp will vary when the system clock is modified > (as a result of an NTP time update for instance). Fixed. > > > > > + for (i = 0; i < VPBE_DISPLAY_MAX_DEVICES; i++) { > > > > + layer = disp_dev->dev[i]; > > > > + /* If streaming is started in this layer */ > > > > + if (!layer->started) > > > > + continue; > > > > + /* Check the field format */ > > > > + if ((V4L2_FIELD_NONE == layer->pix_fmt.field) && > > > > + (event & OSD_END_OF_FRAME)) { > > > > + /* Progressive mode */ > > > > + if (layer_first_int[i]) { > > > > + layer_first_int[i] = 0; > > > > + continue; > > > > + } > > > > + /* > > > > + * Mark status of the cur_frm to > > > > + * done and unlock semaphore on it > > > > + */ > > > > + > > > > + if (layer->cur_frm != layer->next_frm) { > > > > + layer->cur_frm->ts = timevalue; > > > > + layer->cur_frm->state = VIDEOBUF_DONE; > > > > > > Please use videobuf2. > > > > I would like to get to videobuf2 as a next set of changes. I want to > > get the Dm6446 driver fisrt, add it with Dm365 and do the videobuf2 > > later. I hope it is okay. > > We're trying to get rid of videobuf1, so accepting new drivers that make use > of videobuf1 is a bit problematic. Have you had a look at videobuf2 ? How > much time do you think it would take to convert this driver to videobuf2 ? > Let's first address all the other issues, and then tackle that one. I have gone through the videobuf2 in a limited way. I can get the changes done for videobuf2, but my major objective is to get this version of the driver in. Immediately after that I can take up videobuf2. > > [snip] > > > > > +/* interrupt service routine */ > > > > +static irqreturn_t venc_isr(int irq, void *arg) { > > > > + static unsigned last_event; > > > > + unsigned event = 0; > > > > + > > > > + if (venc_is_second_field()) > > > > + event |= VENC_SECOND_FIELD; > > > > + else > > > > + event |= VENC_FIRST_FIELD; > > > > + > > > > + if (event == (last_event & ~VENC_END_OF_FRAME)) { > > > > + /* > > > > + * If the display is non-interlaced, then we need to > > > > + flag > > > > the + * end-of-frame event at every interrupt regardless of > > > > the + * value of the FIDST bit. We can conclude that the > > > > display is + * non-interlaced if the value of the FIDST bit > > > > is unchanged + * from the previous interrupt. > > > > + */ > > > > > > What about checking pix_fmt.field instead ? > > > > Not sure what you mean here. We get the FIRST or second field event > > from the hardware so we need to check the register value rather than > > pix_fmt.field. > > Interlacing is configured by userspace. When configured in interlaced mode, I > expect the device to alternate fields. When configured in progressive mode, I > expect it to always return the same field. If that's correct, the FIDST bit > is only needed to identify the active field when configured in interlaced > mode. > pix_fmt.field can be use to check whether we're in interlaced or progressive > mode. In the isr we check both for the hardware setting and the pix_fmt.field if you see. It meant as a double check. I would like to keep it this way if you do not mind. > > [snip] > > > > > +static int vpbe_display_querycap(struct file *file, void *priv, > > > > + struct v4l2_capability *cap) { > > > > + struct vpbe_fh *fh = file->private_data; > > > > + struct vpbe_display_obj *layer = fh->layer; > > > > + > > > > + v4l2_dbg(1, debug, &vpbe_dev->v4l2_dev, > > > > + "VIDIOC_QUERYCAP, layer id = %d\n", layer->device_id); > > > > > > Do you really need a debugging call here ? > > > > I am Ok either ways. When debugging is enabled, it is just one of the > > data points since there are multiple windows. > > You could leave it, but a debug call in the querycap handler doesn't look > very useful to me. > > > > > + *cap = vpbe_display_videocap; > > > > + > > > > + return 0; > > > > +} > > [snip] > > > > > +static int vpbe_display_g_fmt(struct file *file, void *priv, > > > > + struct v4l2_format *fmt) { > > > > + struct vpbe_fh *fh = file->private_data; > > > > + struct vpbe_display_obj *layer = fh->layer; > > > > + > > > > + v4l2_dbg(1, debug, &vpbe_dev->v4l2_dev, > > > > + "VIDIOC_G_FMT, layer id = %d\n", > > > > + layer->device_id); > > > > + > > > > + /* If buffer type is video output */ > > > > + if (V4L2_BUF_TYPE_VIDEO_OUTPUT == fmt->type) { > > > > + struct v4l2_pix_format *pixfmt = &fmt->fmt.pix; > > > > + /* Fill in the information about format */ > > > > + *pixfmt = layer->pix_fmt; > > > > > > I don't see anything wrong in doing > > > > > > fmt->fmt.pix = layer->pix_fmt; > > > > > > directly. > > > > Wel,. In the past patches we had a large amount of multiple > > indirections, and as part of a suggestion on open source I removed all > > of them with a general rule of not having more than 2 indirections. > > What is your take on this? How many indirection levels do you allow? > > There's no hard rule for that. I usually use intermediate pointers when the > number of indirection levels grow too high, except when I only need to > perform the indirection once or twice, like in this case. OK. Addressed. > > > > > + } else { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, "invalid type\n"); > > > > + return -EINVAL; > > > > + } > > > > + > > > > + return 0; > > > > +} > > [snip] > > > > > +static int vpbe_display_s_fmt(struct file *file, void *priv, > > > > + struct v4l2_format *fmt) { > > > > + int ret = 0; > > > > + struct vpbe_fh *fh = file->private_data; > > > > + struct vpbe_display *disp_dev = video_drvdata(file); > > > > + struct vpbe_display_obj *layer = fh->layer; > > > > + struct osd_layer_config *cfg = &layer->layer_info.config; > > > > > > Variables are often declared in longuest to shortest line order in > > > kernel drivers. It might not be a requirement though, but I find it > > > to make code more readable. > > > > cannot do as suggested since the structure variable assignments have > > dependency on previous structure variables. > > Oops, my bad. > > > > > + > > > > + v4l2_dbg(1, debug, &vpbe_dev->v4l2_dev, > > > > + "VIDIOC_S_FMT, layer id = %d\n", > > > > + layer->device_id); > > > > + > > > > + /* If streaming is started, return error */ > > > > + if (layer->started) { > > > > > > I'm pretty sure there's a race condition here. > > > > Not sure about this. The entire driver is under V4L2 lock per layer > > handle and it would not allow another call to come here once in. > > I missed that. Probably because I dislike that lock :-) > > > Can you elaborate how is it a race condition? > > > > > > + v4l2_err(&vpbe_dev->v4l2_dev, "Streaming is started\n"); > > > > + return -EBUSY; > > > > + } > > > > + if (V4L2_BUF_TYPE_VIDEO_OUTPUT != fmt->type) { > > > > + v4l2_dbg(1, debug, &vpbe_dev->v4l2_dev, "invalid type\n"); > > > > + return -EINVAL; > > > > + } else { > > > > + struct v4l2_pix_format *pixfmt = &fmt->fmt.pix; > > > > + /* Check for valid pixel format */ > > > > + ret = vpbe_try_format(disp_dev, pixfmt, 1); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + /* YUV420 is requested, check availability of the > > > > + other video window */ > > > > + > > > > + layer->pix_fmt = *pixfmt; > > > > + > > > > + /* Get osd layer config */ > > > > + osd_device->ops.get_layer_config(osd_device, > > > > + layer->layer_info.id, cfg); > > > > + /* Store the pixel format in the layer object */ > > > > + cfg->xsize = pixfmt->width; > > > > + cfg->ysize = pixfmt->height; > > > > + cfg->line_length = pixfmt->bytesperline; > > > > + cfg->ypos = 0; > > > > + cfg->xpos = 0; > > > > + cfg->interlaced = > > > > + vpbe_dev->current_timings.interlaced; > > > > + > > > > + /* Change of the default pixel format for both video > > > > windows */ + if (V4L2_PIX_FMT_NV12 == pixfmt->pixelformat) { > > > > + struct vpbe_display_obj *otherlayer; > > > > > > If the requested format isn't NV12, cfg->pixfmt won't be modified. > > > If it has been set to NV12 by a previous S_FMT call, it won't become > > > YUYV. Is that intentional ? > > > > It is reset to YUYV as part of Open. So it is changed only if it is NV12. > > As stated below, you shouldn't reset formats in open(). Addressed. > > > > > + cfg->pixfmt = PIXFMT_NV12; > > > > + otherlayer = _vpbe_display_get_other_win(disp_dev, > > > > + layer); > > > > + otherlayer->layer_info.config.pixfmt = PIXFMT_NV12; > > > > + } > > > > + > > > > + /* Set the layer config in the osd window */ > > > > + ret = osd_device->ops.set_layer_config(osd_device, > > > > + layer->layer_info.id, cfg); > > > > + if (ret < 0) { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, > > > > + "Error in S_FMT params:\n"); > > > > + return -EINVAL; > > > > + } > > > > + > > > > + /* Readback and fill the local copy of current pix > > > > + format > > > > */ + osd_device->ops.get_layer_config(osd_device, > > > > + layer->layer_info.id, cfg); > > > > + > > > > + /* verify if readback values are as expected */ > > > > + if (layer->pix_fmt.width != cfg->xsize || > > > > + layer->pix_fmt.height != cfg->ysize || > > > > + layer->pix_fmt.bytesperline != layer->layer_info. > > > > + config.line_length || (cfg->interlaced && > > > > + layer->pix_fmt.field != V4L2_FIELD_INTERLACED) || > > > > + (!cfg->interlaced && layer->pix_fmt.field != > > > > + V4L2_FIELD_NONE)) { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, > > > > + "mismatch:layer conf params:\n"); > > > > + return -EINVAL; > > > > + } > > > > + } > > > > + > > > > + return 0; > > > > +} > > [snip] > > > > > +/** > > > > + * vpbe_display_g_std - Get the standard in the current encoder > > > > + * > > > > + * Get the standard in the current encoder. Return the status. 0 > > > > +- > > > > success + * -EINVAL on error > > > > + */ > > > > +static int vpbe_display_g_std(struct file *file, void *priv, > > > > + v4l2_std_id *std_id) { > > > > + v4l2_dbg(1, debug, &vpbe_dev->v4l2_dev, "VIDIOC_G_STD\n"); > > > > + > > > > + /* Get the standard from the current encoder */ > > > > + if (vpbe_dev->current_timings.timings_type & VPBE_ENC_STD) { > > > > + *std_id = vpbe_dev->current_timings.timings.std_id; > > > > + return 0; > > > > + } > > > > + return -EINVAL; > > > > > > Where do you set timings_type ? When can this return an error ? > > > > It can return an error if the driver is set to a DV_PRESET mode. > > timings_type would tell whether is is an SD standard or a DV_PRESET. > > But you don't seem to set it anywhere. It is set in set_dv_presets and s_std, but is part of vpbe.c file. > > > > > +} > > [snip] > > > > > +static int vpbe_display_cfg_layer_default(enum > > > > +vpbe_display_device_id > > > > id, + struct vpbe_display *disp_dev) > > > > +{ > > > > + int err = 0; > > > > + struct osd_layer_config *layer_config; > > > > + struct vpbe_display_obj *layer = disp_dev->dev[id]; > > > > + struct osd_layer_config *cfg = &layer->layer_info.config; > > > > + > > > > + /* First claim the layer for this device */ > > > > + err = osd_device->ops.request_layer(osd_device, > > > > + layer->layer_info.id); > > > > + if (err < 0) { > > > > + /* Couldn't get layer */ > > > > + v4l2_err(&vpbe_dev->v4l2_dev, > > > > + "Display Manager failed to allocate layer\n"); > > > > + return -EBUSY; > > > > + } > > > > + > > > > + layer_config = cfg; > > > > + /* Set the default image and crop values */ > > > > + layer_config->pixfmt = PIXFMT_YCbCrI; > > > > + layer->pix_fmt.pixelformat = V4L2_PIX_FMT_UYVY; > > > > + layer->pix_fmt.bytesperline = layer_config->line_length = > > > > + vpbe_dev->current_timings.xres * 2; > > > > + > > > > + layer->pix_fmt.width = layer_config->xsize = > > > > + vpbe_dev->current_timings.xres; > > > > + layer->pix_fmt.height = layer_config->ysize = > > > > + vpbe_dev->current_timings.yres; > > > > + layer->pix_fmt.sizeimage = > > > > + layer->pix_fmt.bytesperline * layer->pix_fmt.height; > > > > + layer_config->xpos = 0; > > > > + layer_config->ypos = 0; > > > > + layer_config->interlaced = > > > > + vpbe_dev->current_timings.interlaced; > > > > > > You shouldn't reinitialized the format every time the device is opened. > > > The previously set format should be kept. > > > > This strictly followed across drivers? I am Ok if that is the expectation. > > It's how V4L2 drivers should behave. Some drivers might not follow that rule, > but that would be a bug :-) Alright. Fixed. > > > > > + > > > > + /* > > > > + * turn off ping-pong buffer and field inversion to fix > > > > + * the image shaking problem in 1080I mode > > > > + */ > > > > + > > > > + if (cfg->interlaced) > > > > + layer->pix_fmt.field = V4L2_FIELD_INTERLACED; > > > > + else > > > > + layer->pix_fmt.field = V4L2_FIELD_NONE; > > > > + > > > > + err = osd_device->ops.set_layer_config(osd_device, > > > > + layer->layer_info.id, > > > > + layer_config); > > > > + if (err < 0) { > > > > + /* Couldn't set layer */ > > > > + v4l2_err(&vpbe_dev->v4l2_dev, > > > > + "Display Manager failed to set osd layer\n"); > > > > + return -EBUSY; > > > > + } > > > > + > > > > + return 0; > > > > +} > > [snip] > > > > > +/* > > > > + * vpbe_display_probe() > > > > + * This function creates device entries by register itself to the > > > > +V4L2 > > > > driver + * and initializes fields of each layer objects > > > > + */ > > > > +static __devinit int vpbe_display_probe(struct platform_device > > > > +*pdev) { > > > > + int i, j = 0, k, err = 0; > > > > + struct vpbe_display *disp_dev; > > > > + struct video_device *vbd = NULL; > > > > + struct vpbe_display_obj *vpbe_display_layer = NULL; > > > > + struct resource *res; > > > > + int irq; > > > > + > > > > + printk(KERN_DEBUG "vpbe_display_probe\n"); > > > > + > > > > + /* Allocate memory for vpbe_display */ > > > > + disp_dev = kzalloc(sizeof(struct vpbe_display), GFP_KERNEL); > > > > + if (!disp_dev) { > > > > + printk(KERN_ERR "ran out of memory\n"); > > > > + return -ENOMEM; > > > > + } > > > > + > > > > + /* Allocate memory for four plane display objects */ > > > > + for (i = 0; i < VPBE_DISPLAY_MAX_DEVICES; i++) { > > > > + disp_dev->dev[i] = > > > > + kmalloc(sizeof(struct vpbe_display_obj), GFP_KERNEL); > > > > + /* If memory allocation fails, return error */ > > > > + if (!disp_dev->dev[i]) { > > > > + printk(KERN_ERR "ran out of memory\n"); > > > > + err = -ENOMEM; > > > > + goto probe_out; > > > > + } > > > > + spin_lock_init(&disp_dev->dev[i]->irqlock); > > > > + mutex_init(&disp_dev->dev[i]->opslock); > > > > + } > > > > + spin_lock_init(&disp_dev->dma_queue_lock); > > > > + > > > > + err = init_vpbe_layer_objects(i); > > > > + if (err) { > > > > + printk(KERN_ERR "Error initializing vpbe display\n"); > > > > + return err; > > > > + } > > > > + > > > > + /* > > > > + * Scan all the platform devices to find the vpbe > > > > + * controller device and get the vpbe_dev object > > > > + */ > > > > + err = bus_for_each_dev(&platform_bus_type, NULL, NULL, > > > > + vpbe_device_get); > > > > + if (err < 0) > > > > + return err; > > > > + > > > > + /* Initialize the vpbe display controller */ > > > > + if (NULL != vpbe_dev->ops.initialize) { > > > > + err = vpbe_dev->ops.initialize(&pdev->dev, vpbe_dev); > > > > + if (err) { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, "Error initing > > > > vpbe\n"); + err = -ENOMEM; > > > > + goto probe_out; > > > > + } > > > > + } > > > > + > > > > + /* check the name of davinci device */ > > > > + if (vpbe_dev->cfg->module_name != NULL) > > > > + strcpy(vpbe_display_videocap.card, > > > > + vpbe_dev->cfg->module_name); > > > > + > > > > + for (i = 0; i < VPBE_DISPLAY_MAX_DEVICES; i++) { > > > > + /* Get the pointer to the layer object */ > > > > + vpbe_display_layer = disp_dev->dev[i]; > > > > + /* Allocate memory for video device */ > > > > + vbd = video_device_alloc(); > > > > + if (vbd == NULL) { > > > > + for (j = 0; j < i; j++) { > > > > + video_device_release( > > > > + disp_dev->dev[j]->video_dev); > > > > + } > > > > + v4l2_err(&vpbe_dev->v4l2_dev, "ran out of > > > > memory\n"); + err = -ENOMEM; > > > > + goto probe_out; > > > > + } > > > > + /* Initialize field of video device */ > > > > + vbd->release = video_device_release; > > > > + vbd->fops = &vpbe_fops; > > > > + vbd->ioctl_ops = &vpbe_ioctl_ops; > > > > + vbd->minor = -1; > > > > + vbd->v4l2_dev = &vpbe_dev->v4l2_dev; > > > > + vbd->lock = &vpbe_display_layer->opslock; > > > > + > > > > + if (vpbe_dev->current_timings.timings_type & > > > > + VPBE_ENC_STD) > > > > { + vbd->tvnorms = (V4L2_STD_525_60 | > > > > V4L2_STD_625_50); + vbd->current_norm = > > > > + vpbe_dev->current_timings.timings.std_id; > > > > + } else > > > > + vbd->current_norm = 0; > > > > + > > > > + snprintf(vbd->name, sizeof(vbd->name), > > > > + "DaVinci_VPBE Display_DRIVER_V%d.%d.%d", > > > > + (VPBE_DISPLAY_VERSION_CODE >> 16) & 0xff, > > > > + (VPBE_DISPLAY_VERSION_CODE >> 8) & 0xff, > > > > + (VPBE_DISPLAY_VERSION_CODE) & 0xff); > > > > + > > > > + /* Set video_dev to the video device */ > > > > + vpbe_display_layer->video_dev = vbd; > > > > + vpbe_display_layer->device_id = i; > > > > + > > > > + vpbe_display_layer->layer_info.id = > > > > + ((i == VPBE_DISPLAY_DEVICE_0) ? WIN_VID0 : WIN_VID1); > > > > + if (display_buf_config_params.numbuffers[i] == 0) > > > > + vpbe_display_layer->memory = V4L2_MEMORY_USERPTR; > > > > + else > > > > + vpbe_display_layer->memory = V4L2_MEMORY_MMAP; > > > > + > > > > + /* Initialize field of the display layer objects */ > > > > + vpbe_display_layer->usrs = 0; > > > > + vpbe_display_layer->io_usrs = 0; > > > > + vpbe_display_layer->started = 0; > > > > + > > > > + /* Initialize prio member of layer object */ > > > > + v4l2_prio_init(&vpbe_display_layer->prio); > > > > + > > > > + /* Register video device */ > > > > + v4l2_info(&vpbe_dev->v4l2_dev, > > > > + "Trying to register VPBE display device.\n"); > > > > + v4l2_info(&vpbe_dev->v4l2_dev, > > > > + "layer=%x,layer->video_dev=%x\n", > > > > + (int)vpbe_display_layer, > > > > + (int)&vpbe_display_layer->video_dev); > > > > + > > > > + err = video_register_device(vpbe_display_layer-> > > > > + video_dev, > > > > + VFL_TYPE_GRABBER, > > > > + vpbe_display_nr[i]); > > > > + if (err) > > > > + goto probe_out; > > > > + /* set the driver data in platform device */ > > > > + platform_set_drvdata(pdev, disp_dev); > > > > + video_set_drvdata(vpbe_display_layer->video_dev, disp_dev); > > > > + } > > > > + > > > > + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); > > > > + if (!res) { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, > > > > + "Unable to get VENC interrupt resource\n"); > > > > + err = -ENODEV; > > > > + goto probe_out; > > > > + } > > > > + irq = res->start; > > > > + if (request_irq(irq, venc_isr, IRQF_DISABLED, VPBE_DISPLAY_DRIVER, > > > > + disp_dev)) { > > > > + v4l2_err(&vpbe_dev->v4l2_dev, "Unable to request > > > > interrupt\n"); + err = -ENODEV; > > > > + goto probe_out; > > > > + } > > > > > > You probably want to get the resources and register the interrupt > > > handler before registering the V4L2 devices, otherwise userspace > > > will be able to open devices before you're done with the initialization. > > > > I do not think anyone would attempt to open the device so soon as the > > boot process is not complete yet. > > Unless you compile the driver as a module. In that case an application could > open the device as soon as it gets registered. hal is known to do that. > > > Also, if the irq is registered before, the interrupts start and the > > driver crashes for lack of initialized structure variables. > > Why would an interrupt occur before the device gets opened ? I got the interrupt and the driver crashed because of initialized pointers if I put this before. I will see why and fix it. > > > > > + printk(KERN_DEBUG "Successfully completed the probing of vpbe > > > > + v4l2 > > > > device\n"); + return 0; > > > > +probe_out: > > > > + kfree(disp_dev); > > > > + > > > > + for (k = 0; k < j; k++) { > > > > + /* Get the pointer to the layer object */ > > > > + vpbe_display_layer = disp_dev->dev[k]; > > > > + /* Unregister video device */ > > > > + video_unregister_device(vpbe_display_layer->video_dev); > > > > + /* Release video device */ > > > > + video_device_release(vpbe_display_layer->video_dev); > > > > + vpbe_display_layer->video_dev = NULL; > > > > + } > > > > + return err; > > > > +} > > > > > > [snip] > > > > > > > +MODULE_DESCRIPTION("TI DMXXX VPBE Display controller"); > > > > > > Should this be "TI DM644x" instead ? > > > > This is a common IP for DM644x, Dm355 and Dm365 for which the patches > > will follow after this set. So I think it is OK. > > What about "TI DM644x/DM355/DM365" then ? DMXXX makes it look like it > supports all DaVinci chips. > > -- > Regards, > > Laurent Pinchart > _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source