-----Original Message----- From: linuxppc-dev-bounces+tmarri=amcc.com@xxxxxxxxxxxxxxxx [mailto:linuxppc-dev-bounces+tmarri=amcc.com@xxxxxxxxxxxxxxxx] On Behalf Of David Laight Sent: Wednesday, January 26, 2011 8:35 AM Cc: linux-usb@xxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx Subject: RE: [PATCH V8 03/10] USB/ppc4xx: Add Synopsys DWC OTG CoreInterface Layer > Also in_le32/out_le32/in_be32/out_be32 are > architecture-specific AFAIK. Isn't the whole patch architecture-specific ? > I'd suggest using readl/writel for LE ops and > __be32_to_cpu(__raw_readl(addr))/__raw_writel(__cpu_to_be32(b),addr) > for BE ops. Since the ppc doesn't have a byteswap instruction (and the LE memory transfers might even be slow!) you really don't want to be doing software byteswap. Not to mention the horrific synchronistion instructions that in_le32() and out_le32() actually contain. I didn't find __raw_readl() when I was looking for asm patterns that byteswapped memory transfers. I did find st_le32() and ld_le32() in arch/powerpc/include/asm/swab.h but that file is actually quite difficult to #include because there is another swab.h that gets included instead. [marri] Initial version of DWC-IP did not have feature to swap endianness. Whereas next versions have it. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
