On 10/22/2015 11:02 AM, Arnd Bergmann wrote: > On Thursday 22 October 2015 08:34:53 Appana Durga Kedareswara Rao wrote: >>> On Thursday 22 October 2015 10:16:02 Kedareswara rao Appana wrote: >>>> The driver only supports memory-mapped I/O [by ioremap()], so >>>> readl/writel is actually the right thing to do, IMO. >>>> During the validation of this driver or IP on ARM 64-bit processor >>>> while sending lot of packets observed that the tx packet drop with >>>> iowrite Putting the barriers for each tx fifo register write fixes >>>> this issue Instead of barriers using writel also fixed this issue. >>>> >>>> Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com> >>> >>> The two should really do the same thing: iowrite32() is just a static >>> inline calling >>> writel() on both ARM32 and ARM64. On which kernel version did you observe >>> the >>> difference? It's possible that an older version used CONFIG_GENERIC_IOMAP, >>> which made this slightly more expensive. >> >> I observed this issue with the 4.0.0 kernel version > > Is it possible that you have nonstandard patches on your kernel? If so, can > you send a diff against the mainline version?
Kedar: Can you please retest this on mainline kernel? We shouldn't have any patches which should influence this. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
