[U-Boot] [PATCH 1/1] USB: Fix strict aliasing in ohci-hcd

Marek Vasut marex at denx.de
Tue Aug 14 19:33:29 CEST 2012


Dear Troy Kisky,

> commit 5f6aa03fda2a0a79940765865c1e4266be8a75f8
>     USB: Fix complaints about strict aliasing in OHCI-HCD
> 
> tried to fix this, but gcc4.4 still complains. So, this
> patch basically reverts the above and does a simpler fix.
> 
> also, the above commit incorrectly changed
> 	/* corresponds to data_buf[4-7] */
> 	datab [1] = 0;
> to
> 
> 	/* corresponds to databuf.u8[4-7] */
> 	databuf.u8[1] = 0;
> 
> This patch also fixes that.
> 
> Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>
> ---
>  drivers/usb/host/ohci-hcd.c |   70
> +++++++++++++++++++------------------------ 1 file changed, 31
> insertions(+), 39 deletions(-)
> 
> diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
> index d24f2f1..9f47351 100644
> --- a/drivers/usb/host/ohci-hcd.c
> +++ b/drivers/usb/host/ohci-hcd.c
> @@ -1261,19 +1261,11 @@ static int ohci_submit_rh_msg(struct usb_device
> *dev, unsigned long pipe, int leni = transfer_len;
>  	int len = 0;
>  	int stat = 0;
> -	__u32 datab[4];
> -	union {
> -		void *ptr;
> -		__u8 *u8;
> -		__u16 *u16;
> -		__u32 *u32;
> -	} databuf;
>  	__u16 bmRType_bReq;
>  	__u16 wValue;
>  	__u16 wIndex;
>  	__u16 wLength;
> -
> -	databuf.u32 = (__u32 *)datab;
> +	ALLOC_ALIGN_BUFFER(__u8, databuf, 16, sizeof(u32));

Ok, pardon my sloppiness in reviews ... but why not alloc this cache aligned? 
That way we'd also circumvent the issues with caches we'd eventually hit anyway.

[...]

The rest is OK.


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