Re: [PATCH 1/3] media/ttusb-budget: remove pci_zalloc_coherent abuse

[Joe Perches]

On Tue, 2018-01-09 at 21:39 +0100, Christoph Hellwig wrote:
> Switch to a plain kzalloc instea of pci_zalloc_coherent to allocate
> memory for the USB DMA.
[]
> diff --git a/drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c 
> b/drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c
[]
> @@ -792,21 +791,15 @@ static void ttusb_free_iso_urbs(struct ttusb *ttusb)
> []
>  static int ttusb_alloc_iso_urbs(struct ttusb *ttusb)
>  {
>       int i;
>  
> -     ttusb->iso_buffer = pci_zalloc_consistent(NULL,
> -                                               ISO_FRAME_SIZE * 
> FRAMES_PER_ISO_BUF * ISO_BUF_COUNT,
> -                                               &ttusb->iso_dma_handle);
> -
> +     ttusb->iso_buffer = kzalloc(ISO_FRAME_SIZE * FRAMES_PER_ISO_BUF *
> +                     ISO_BUF_COUNT, GFP_KERNEL);
>       if (!ttusb->iso_buffer) {
>               dprintk("%s: pci_alloc_consistent - not enough memory\n",
>                       __func__);

This message doesn't make sense anymore and it might as well
be deleted.

And it might be better to use kcalloc

        ttusb->iso_buffer = kcalloc(FRAMES_PER_ISO_BUF * ISO_BUF_COUNT,
                                    ISO_FRAME_SIZE, GFP_KERNEL);