Re: [PATCH v2] USB: host: Use zeroing memory allocator rather than allocator/memset

[Mathias Nyman]

On 30.12.2017 22:03, Himanshu Jha wrote:
> Use dma_zalloc_coherent for allocating zeroed
> memory and remove unnecessary memset function.
>
> Done using Coccinelle.
> Generated-by: scripts/coccinelle/api/alloc/kzalloc-simple.cocci
> 0-day tested with no failures.
>
> Suggested-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
> Signed-off-by: Himanshu Jha <himanshujha199640@xxxxxxxxx>
> ---
> v2:
>     -align argumenst as they were before applying the SmPL rule.
>
>   drivers/usb/host/uhci-hcd.c | 7 +++----
>   drivers/usb/host/xhci-mem.c | 7 ++-----
>   2 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
> index f5c9021..ac53398 100644
> --- a/drivers/usb/host/uhci-hcd.c
> +++ b/drivers/usb/host/uhci-hcd.c
> @@ -600,15 +600,14 @@ static int uhci_start(struct usb_hcd *hcd)
>   	uhci->dentry = dentry;
>   #endif
>   
> -	uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
> -			UHCI_NUMFRAMES * sizeof(*uhci->frame),
> -			&uhci->frame_dma_handle, GFP_KERNEL);
> +	uhci->frame = dma_zalloc_coherent(uhci_dev(uhci),
> +			UHCI_NUMFRAMES * sizeof(*uhci->frame),
> +			&uhci->frame_dma_handle, GFP_KERNEL);
>   	if (!uhci->frame) {
>   		dev_err(uhci_dev(uhci),
>   			"unable to allocate consistent memory for frame list\n");
>   		goto err_alloc_frame;
>   	}
> -	memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
>   
>   	uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
>   			GFP_KERNEL);
> diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
> index 554a8a5..332420d 100644
> --- a/drivers/usb/host/xhci-mem.c
> +++ b/drivers/usb/host/xhci-mem.c
> @@ -1782,14 +1782,11 @@ int xhci_alloc_erst(struct xhci_hcd *xhci,
>   	struct xhci_erst_entry *entry;
>   
>   	size = sizeof(struct xhci_erst_entry) * evt_ring->num_segs;
> -	erst->entries = dma_alloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
> -					   size,
> -					   &erst->erst_dma_addr,
> -					   flags);
> +	erst->entries = dma_zalloc_coherent(xhci_to_hcd(xhci)->self.sysdev,
> +					    size, &erst->erst_dma_addr, flags);
>   	if (!erst->entries)
>   		return -ENOMEM;
>   
> -	memset(erst->entries, 0, size);
>   	erst->num_entries = evt_ring->num_segs;
>   
>   	seg = evt_ring->first_seg;

For the xhci part:
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>