From e392255766071c8cac480da3a9ae4f94e56d7cbc Mon Sep 17 00:00:00 2001 From: Mark Cave-Ayland Date: Wed, 7 Apr 2021 20:57:51 +0100 Subject: [PATCH] esp: rework write_response() to avoid using the FIFO for DMA transactions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The code for write_response() has always used the FIFO to store the data for the status/message in phases, even for DMA transactions. Switch to using a separate buffer that can be used directly for DMA transactions and restrict the FIFO use to the non-DMA case. Signed-off-by: Mark Cave-Ayland Tested-by: Alexander Bulekov Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20210407195801.685-3-mark.cave-ayland@ilande.co.uk> --- hw/scsi/esp.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index a79196f3f3..2584ec6fb1 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -445,18 +445,16 @@ static void write_response_pdma_cb(ESPState *s) static void write_response(ESPState *s) { - uint32_t n; + uint8_t buf[2]; trace_esp_write_response(s->status); - fifo8_reset(&s->fifo); - esp_fifo_push(s, s->status); - esp_fifo_push(s, 0); + buf[0] = s->status; + buf[1] = 0; if (s->dma) { if (s->dma_memory_write) { - s->dma_memory_write(s->dma_opaque, - (uint8_t *)fifo8_pop_buf(&s->fifo, 2, &n), 2); + s->dma_memory_write(s->dma_opaque, buf, 2); s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST; s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC; s->rregs[ESP_RSEQ] = SEQ_CD; @@ -466,7 +464,8 @@ static void write_response(ESPState *s) return; } } else { - s->ti_size = 2; + fifo8_reset(&s->fifo); + fifo8_push_all(&s->fifo, buf, 2); s->rregs[ESP_RFLAGS] = 2; } esp_raise_irq(s);