Hi Tomoki,
Em Sat, 3 Mar 2018 21:20:17 +0900
tomoki.sekiy...@gmail.com escreveu:
> From: Tomoki Sekiyama <tomoki.sekiy...@gmail.com>
>
> 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.sekiy...@gmail.com>
> ---
> 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
