Hi Tomoki, Em Sat, 3 Mar 2018 21:20:17 +0900 tomoki.sekiyama@xxxxxxxxx escreveu: > From: Tomoki Sekiyama <tomoki.sekiyama@xxxxxxxxx> > > On some architectures such as arm64, siano chip based TV-tuner > USB devices are not recognized correctly due to coherent memory > allocation failure with the following error: > > [ 663.556135] usbcore: deregistering interface driver smsusb > [ 683.624809] smsusb:smsusb_probe: board id=18, interface number 0 > [ 683.633530] smsusb:smsusb_init_device: smscore_register_device(...) failed, rc -12 > [ 683.641501] smsusb:smsusb_probe: Device initialized with return code -12 > [ 683.652978] smsusb: probe of 1-1:1.0 failed with error -12 > > This is caused by dma_alloc_coherent(NULL, ...) returning NULL in > smscoreapi.c. > > To fix this error, usb_alloc_coherent() must be used for DMA > memory allocation for USB devices in such architectures. Actually, I was thinking on taking a different approach, for all media USB devices: to let USB core to do the DMA mapping itself, and not use coherent memory. E. g. something like the approach taken on this patch: https://patchwork.linuxtv.org/patch/47592/ That should give an additional performance improvements to the driver when used on non-x86 hardware. > > v2: non-usb `device' is also be passed to dma_alloc_coherent() > > Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@xxxxxxxxx> > --- > drivers/media/common/siano/smscoreapi.c | 36 ++++++++++++++++++++++++--------- > drivers/media/common/siano/smscoreapi.h | 2 ++ > drivers/media/usb/siano/smsusb.c | 1 + > 3 files changed, 29 insertions(+), 10 deletions(-) > > diff --git a/drivers/media/common/siano/smscoreapi.c b/drivers/media/common/siano/smscoreapi.c > index c5c827e11b64..34622b562963 100644 > --- a/drivers/media/common/siano/smscoreapi.c > +++ b/drivers/media/common/siano/smscoreapi.c > @@ -690,17 +690,24 @@ int smscore_register_device(struct smsdevice_params_t *params, > > /* alloc common buffer */ > dev->common_buffer_size = params->buffer_size * params->num_buffers; > - dev->common_buffer = dma_alloc_coherent(NULL, dev->common_buffer_size, > - &dev->common_buffer_phys, > - GFP_KERNEL | GFP_DMA); > - if (!dev->common_buffer) { > + if (params->usb_device) > + buffer = usb_alloc_coherent(params->usb_device, > + dev->common_buffer_size, > + GFP_KERNEL | GFP_DMA, > + &dev->common_buffer_phys); > + else > + buffer = dma_alloc_coherent(params->device, > + dev->common_buffer_size, > + &dev->common_buffer_phys, > + GFP_KERNEL | GFP_DMA); > + if (!buffer) { > smscore_unregister_device(dev); > return -ENOMEM; > } > + dev->common_buffer = buffer; > > /* prepare dma buffers */ > - for (buffer = dev->common_buffer; > - dev->num_buffers < params->num_buffers; > + for (; dev->num_buffers < params->num_buffers; > dev->num_buffers++, buffer += params->buffer_size) { > struct smscore_buffer_t *cb; > > @@ -720,6 +727,7 @@ int smscore_register_device(struct smsdevice_params_t *params, > dev->board_id = SMS_BOARD_UNKNOWN; > dev->context = params->context; > dev->device = params->device; > + dev->usb_device = params->usb_device; > dev->setmode_handler = params->setmode_handler; > dev->detectmode_handler = params->detectmode_handler; > dev->sendrequest_handler = params->sendrequest_handler; > @@ -1231,10 +1239,18 @@ void smscore_unregister_device(struct smscore_device_t *coredev) > > pr_debug("freed %d buffers\n", num_buffers); > > - if (coredev->common_buffer) > - dma_free_coherent(NULL, coredev->common_buffer_size, > - coredev->common_buffer, coredev->common_buffer_phys); > - > + if (coredev->common_buffer) { > + if (coredev->usb_device) > + usb_free_coherent(coredev->usb_device, > + coredev->common_buffer_size, > + coredev->common_buffer, > + coredev->common_buffer_phys); > + else > + dma_free_coherent(coredev->device, > + coredev->common_buffer_size, > + coredev->common_buffer, > + coredev->common_buffer_phys); > + } > kfree(coredev->fw_buf); > > list_del(&coredev->entry); > diff --git a/drivers/media/common/siano/smscoreapi.h b/drivers/media/common/siano/smscoreapi.h > index 4cc39e4a8318..134c69f7ea7b 100644 > --- a/drivers/media/common/siano/smscoreapi.h > +++ b/drivers/media/common/siano/smscoreapi.h > @@ -134,6 +134,7 @@ struct smscore_buffer_t { > > struct smsdevice_params_t { > struct device *device; > + struct usb_device *usb_device; > > int buffer_size; > int num_buffers; > @@ -176,6 +177,7 @@ struct smscore_device_t { > > void *context; > struct device *device; > + struct usb_device *usb_device; > > char devpath[32]; > unsigned long device_flags; > diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c > index f13e4b01b5a5..3c605a573ce4 100644 > --- a/drivers/media/usb/siano/smsusb.c > +++ b/drivers/media/usb/siano/smsusb.c > @@ -446,6 +446,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) > dev->in_ep, dev->out_ep); > > params.device = &dev->udev->dev; > + params.usb_device = dev->udev; > params.buffer_size = dev->buffer_size; > params.num_buffers = MAX_BUFFERS; > params.sendrequest_handler = smsusb_sendrequest; Thanks, Mauro
