[U-Boot] [PATCH 4/4] USB:gadget:designware Fix memory nonalignment issue

[Marek Vasut]

Dear Amit Virdi,

> Dear Marek,
> 
> On 3/5/2012 11:51 PM, Marek Vasut wrote:
> > Dear Amit Virdi,
> > 
> >> From: Shiraz Hashim<shiraz.hashim at st.com>
> >> 
> >> While receiving packets from FIFO sometimes the buffer provided was
> >> nonaligned. Fix this by taking a temporary aligned buffer and then
> >> copying the content to nonaligned buffer.
> >> 
> >> Signed-off-by: Shiraz Hashim<shiraz.hashim at st.com>
> >> Signed-off-by: Amit Virdi<amit.virdi at st.com>
> >> ---
> >> 
> >>   drivers/usb/gadget/designware_udc.c |   15 ++++++++++++++-
> >>   1 files changed, 14 insertions(+), 1 deletions(-)
> >> 
> >> diff --git a/drivers/usb/gadget/designware_udc.c
> >> b/drivers/usb/gadget/designware_udc.c index d4b53a2..878123c 100644
> >> --- a/drivers/usb/gadget/designware_udc.c
> >> +++ b/drivers/usb/gadget/designware_udc.c
> >> @@ -202,6 +202,7 @@ static int usbgetpckfromfifo(int epNum, u8 *bufp,
> >> u32 len) u32 i, nw, nb;
> >> 
> >>   	u32 *wrdp;
> >>   	u8 *bytp;
> >> 
> >> +	u32 tmp[128];
> >> 
> >>   	if (readl(&udc_regs_p->dev_stat)&  DEV_STAT_RXFIFO_EMPTY)
> >>   	
> >>   		return -1;
> >> 
> >> @@ -209,7 +210,12 @@ static int usbgetpckfromfifo(int epNum, u8 *bufp,
> >> u32 len) nw = len / sizeof(u32);
> >> 
> >>   	nb = len % sizeof(u32);
> >> 
> >> -	wrdp = (u32 *)bufp;
> >> +	/* use tmp buf if bufp is not word aligned */
> >> +	if ((int)bufp&  0x3)
> >> +		wrdp = (u32 *)&tmp[0];
> >> +	else
> >> +		wrdp = (u32 *)bufp;
> >> +
> >> 
> >>   	for (i = 0; i<  nw; i++) {
> >>   	
> >>   		writel(readl(fifo_ptr), wrdp);
> >>   		wrdp++;
> >> 
> >> @@ -223,6 +229,13 @@ static int usbgetpckfromfifo(int epNum, u8 *bufp,
> >> u32 len) }
> >> 
> >>   	readl(&outep_regs_p[epNum].write_done);
> >> 
> >> +	/* copy back tmp buffer to bufp if bufp is not word aligned */
> >> +	if ((int)bufp&  0x3) {
> >> +		bytp = (u8 *)&tmp[0];
> >> +		for (i = 0; i<  len; i++)
> >> +			bufp[i] = bytp[i];
> >> +	}
> >> +
> >> 
> >>   	return 0;
> >>   
> >>   }
> > 
> > This addresses EHCI cache problem, that's why you need bounce buffer,
> > right?
> 
> No. The problem was we were copying data word-by-word to a non-word
> aligned memory in the USB gadget. So, this is different from the USB
> host controller issue.
> 

I see ... why isn't buffer aligned by the usb stack then?

Thanks!

> 
> Thanks n Regards
> Amit Virdi
> 
> > This is the patch from Puneet, can you give it a go and tell me if EHCI
> > works for you without 4/4 patch from your series or do you still see
> > issues?
> > 
> > http://permalink.gmane.org/gmane.comp.boot-loaders.u-boot/126447
> > 
> > Thanks in advance!
> > 
> > Best regards,
> > Marek Vasut
> > .