Re: [PATCH v4 05/10] net/fec: add dual fec support for mx28
From: Shawn Guo <hidden>
Date: 2011-01-14 13:08:51
Also in:
linux-arm-kernel
On Fri, Jan 14, 2011 at 08:52:23AM +0100, Uwe Kleine-König wrote:
On Fri, Jan 14, 2011 at 01:48:40PM +0800, Shawn Guo wrote:quoted
Hi Uwe, On Thu, Jan 13, 2011 at 03:48:05PM +0100, Uwe Kleine-König wrote: [...]quoted
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+/* Controller is ENET-MAC */ +#define FEC_QUIRK_ENET_MAC (1 << 0)does this really qualify to be a quirk?My understanding is that ENET-MAC is a type of "quirky" FEC controller.quoted
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+/* Controller needs driver to swap frame */ +#define FEC_QUIRK_SWAP_FRAME (1 << 1)IMHO this is a bit misnamed. FEC_QUIRK_NEEDS_BE_DATA or similar would be more accurate.When your make this change, you may want to pick a better name for function swap_buffer too. [...]quoted
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+static void *swap_buffer(void *bufaddr, int len) +{ + int i; + unsigned int *buf = bufaddr; + + for (i = 0; i < (len + 3) / 4; i++, buf++) + *buf = cpu_to_be32(*buf);if len isn't a multiple of 4 this accesses bytes behind len. Is this generally OK here? (E.g. because skbs always have a length that is a multiple of 4?)The len may not be a multiple of 4. But I believe bufaddr is always a buffer allocated in a length that is a multiple of 4, and the 1~3 bytes exceeding the len very likely has no data that matters. But yes, it deserves a safer implementation.Did you test what happens if bufaddr isn't aligned? Does it work at all then?
I see many calls passing a len that is not a multiple of 4, but it works good. -- Regards, Shawn