From 743d8736458d3f939fb957835f42ecc3e2d0f75c Mon Sep 17 00:00:00 2001 From: Mark Cave-Ayland Date: Sun, 24 Mar 2024 19:17:03 +0000 Subject: [PATCH] esp.c: introduce esp_update_drq() and update esp_fifo_{push, pop}_buf() to use it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This new function sets the DRQ line correctly according to the current transfer mode, direction and FIFO contents. Update esp_fifo_push_buf() and esp_fifo_pop_buf() to use it so that DRQ is always set correctly when reading/writing multiple bytes to/from the FIFO. Signed-off-by: Mark Cave-Ayland Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Paolo Bonzini Message-Id: <20240324191707.623175-15-mark.cave-ayland@ilande.co.uk> Signed-off-by: Mark Cave-Ayland --- hw/scsi/esp.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 9e35c00927..6fd1a12f23 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -124,6 +124,48 @@ void esp_request_cancelled(SCSIRequest *req) } } +static void esp_update_drq(ESPState *s) +{ + bool to_device; + + switch (esp_get_phase(s)) { + case STAT_MO: + case STAT_CD: + case STAT_DO: + to_device = true; + break; + + case STAT_DI: + case STAT_ST: + case STAT_MI: + to_device = false; + break; + + default: + return; + } + + if (s->dma) { + /* DMA request so update DRQ according to transfer direction */ + if (to_device) { + if (fifo8_num_free(&s->fifo) < 2) { + esp_lower_drq(s); + } else { + esp_raise_drq(s); + } + } else { + if (fifo8_num_used(&s->fifo) < 2) { + esp_lower_drq(s); + } else { + esp_raise_drq(s); + } + } + } else { + /* Not a DMA request */ + esp_lower_drq(s); + } +} + static void esp_fifo_push(ESPState *s, uint8_t val) { if (fifo8_num_used(&s->fifo) == s->fifo.capacity) { @@ -137,6 +179,7 @@ static void esp_fifo_push(ESPState *s, uint8_t val) static void esp_fifo_push_buf(ESPState *s, uint8_t *buf, int len) { fifo8_push_all(&s->fifo, buf, len); + esp_update_drq(s); } static uint8_t esp_fifo_pop(ESPState *s) @@ -180,7 +223,10 @@ static uint32_t esp_fifo8_pop_buf(Fifo8 *fifo, uint8_t *dest, int maxlen) static uint32_t esp_fifo_pop_buf(ESPState *s, uint8_t *dest, int maxlen) { - return esp_fifo8_pop_buf(&s->fifo, dest, maxlen); + uint32_t len = esp_fifo8_pop_buf(&s->fifo, dest, maxlen); + + esp_update_drq(s); + return len; } static uint32_t esp_get_tc(ESPState *s)