From 31afe04586efeccb80cc36ffafcd0e32a3245ffb Mon Sep 17 00:00:00 2001 From: Tommy Wu Date: Thu, 25 May 2023 10:37:51 +0100 Subject: [PATCH] hw/dma/xilinx_axidma: Check DMASR.HALTED to prevent infinite loop. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When we receive a packet from the xilinx_axienet and then try to s2mem through the xilinx_axidma, if the descriptor ring buffer is full in the xilinx axidma driver, we’ll assert the DMASR.HALTED in the function : stream_process_s2mem and return 0. In the end, we’ll be stuck in an infinite loop in axienet_eth_rx_notify. This patch checks the DMASR.HALTED state when we try to push data from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted, we will not keep pushing the data and then prevent the infinte loop. Signed-off-by: Tommy Wu Reviewed-by: Edgar E. Iglesias Reviewed-by: Frank Chang Message-id: 20230519062137.1251741-1-tommy.wu@sifive.com Signed-off-by: Peter Maydell --- hw/dma/xilinx_axidma.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c index 6030c76435..12c90267df 100644 --- a/hw/dma/xilinx_axidma.c +++ b/hw/dma/xilinx_axidma.c @@ -168,6 +168,11 @@ static inline int stream_idle(struct Stream *s) return !!(s->regs[R_DMASR] & DMASR_IDLE); } +static inline int stream_halted(struct Stream *s) +{ + return !!(s->regs[R_DMASR] & DMASR_HALTED); +} + static void stream_reset(struct Stream *s) { s->regs[R_DMASR] = DMASR_HALTED; /* starts up halted. */ @@ -269,7 +274,7 @@ static void stream_process_mem2s(struct Stream *s, StreamSink *tx_data_dev, uint64_t addr; bool eop; - if (!stream_running(s) || stream_idle(s)) { + if (!stream_running(s) || stream_idle(s) || stream_halted(s)) { return; } @@ -326,7 +331,7 @@ static size_t stream_process_s2mem(struct Stream *s, unsigned char *buf, unsigned int rxlen; size_t pos = 0; - if (!stream_running(s) || stream_idle(s)) { + if (!stream_running(s) || stream_idle(s) || stream_halted(s)) { return 0; } @@ -407,7 +412,7 @@ xilinx_axidma_data_stream_can_push(StreamSink *obj, XilinxAXIDMAStreamSink *ds = XILINX_AXI_DMA_DATA_STREAM(obj); struct Stream *s = &ds->dma->streams[1]; - if (!stream_running(s) || stream_idle(s)) { + if (!stream_running(s) || stream_idle(s) || stream_halted(s)) { ds->dma->notify = notify; ds->dma->notify_opaque = notify_opaque; return false;