Hmm good question. I went with flush because that's what's done in the transmit function:
addr = (ulong) ptr; addr &= ~(ARCH_DMA_MINALIGN - 1); size = roundup(len, ARCH_DMA_MINALIGN); flush_dcache_range(addr, addr + size);
addr = (ulong)priv->rxbuffers; addr &= ~(ARCH_DMA_MINALIGN - 1); size = roundup((RX_BUF * PKTSIZE_ALIGN), ARCH_DMA_MINALIGN); flush_dcache_range(addr, addr + size); barrier();
But since we actually want the uncached data invalidation seems logical. I have to admit though, I don't have much experience with caches. This patch completely fixed my problem... Maybe somebody with a bit more expertise can add their opinion?
Regards, Stefan
-----Ursprüngliche Nachricht----- Von: Bin Meng [mailto:bmeng.cn@gmail.com] Gesendet: Donnerstag, 13. Dezember 2018 14:13 An: Stefan Theil Cc: U-Boot Mailing List Betreff: Re: [U-Boot] [PATCH] zynq-gem: Flush cache before handing RX packet to receive handler
On Thu, Dec 13, 2018 at 6:18 PM Stefan Theil stefan.theil@mixed-mode.de wrote:
The cache was only flushed before *transmitting* packets, but not when receiving them, leading to an issue where new packets were handed to the receive handler with old contents in cache. This only happens when a lot of packets are received without sending packages every now and then.
Signed-off-by: Stefan Theil stefan.theil@mixed-mode.de
drivers/net/zynq_gem.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/zynq_gem.c b/drivers/net/zynq_gem.c index 9bd79b198a..5825b6dd99 100644 --- a/drivers/net/zynq_gem.c +++ b/drivers/net/zynq_gem.c @@ -621,6 +621,9 @@ static int zynq_gem_recv(struct udevice *dev, int flags, uchar **packetp)
*packetp = (uchar *)(uintptr_t)addr;
flush_dcache_range(addr, addr + roundup(PKTSIZE_ALIGN,- ARCH_DMA_MINALIGN));
Shouldn't it be invalidate_dcache_range()?
barrier();return frame_len;}
Regards, Bin