@@ -604,12 +604,13 @@ static void do_dma_pdma_cb(ESPState *s)
s->async_len -= n;
s->ti_size += n;
- if (s->async_len == 0) {
+ if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
+ /* Defer until the scsi layer has completed */
scsi_req_continue(s->current_req);
return;
}
- if (esp_get_tc(s) == 0) {
+ if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
esp_lower_drq(s);
esp_dma_done(s);
}
@@ -706,24 +707,30 @@ static void esp_do_dma(ESPState *s)
s->async_len -= len;
s->ti_size += len;
- if (s->async_len == 0) {
+ if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
+ /* Defer until the scsi layer has completed */
scsi_req_continue(s->current_req);
- /*
- * If there is still data to be read from the device then
- * complete the DMA operation immediately. Otherwise defer
- * until the scsi layer has completed.
- */
return;
}
- if (esp_get_tc(s) == 0) {
- /* Partially filled a scsi buffer. Complete immediately. */
+ if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
esp_dma_done(s);
esp_lower_drq(s);
}
} else {
esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
esp_raise_drq(s);
+
+ if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
+ /* Defer until the scsi layer has completed */
+ scsi_req_continue(s->current_req);
+ return;
+ }
+
+ if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
+ esp_dma_done(s);
+ esp_lower_drq(s);
+ }
}
} else {
if (s->dma_memory_write) {
@@ -734,13 +741,13 @@ static void esp_do_dma(ESPState *s)
s->async_len -= len;
s->ti_size -= len;
- if (s->async_len == 0) {
+ if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
+ /* Defer until the scsi layer has completed */
scsi_req_continue(s->current_req);
return;
}
- if (esp_get_tc(s) == 0) {
- /* Partially filled a scsi buffer. Complete immediately. */
+ if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
esp_dma_done(s);
esp_lower_drq(s);
}
@@ -754,6 +761,17 @@ static void esp_do_dma(ESPState *s)
esp_set_tc(s, esp_get_tc(s) - len);
esp_set_pdma_cb(s, DO_DMA_PDMA_CB);
esp_raise_drq(s);
+
+ if (s->async_len == 0 && fifo8_num_used(&s->fifo) < 2) {
+ /* Defer until the scsi layer has completed */
+ scsi_req_continue(s->current_req);
+ return;
+ }
+
+ if (esp_get_tc(s) == 0 && fifo8_num_used(&s->fifo) < 2) {
+ esp_lower_drq(s);
+ esp_dma_done(s);
+ }
}
}
}
Ensure that the async_len checks for requesting data from the SCSI layer and the TC == 0 checks to detect the end of the DMA transfer are consistent in both do_dma_pdma_cb() and esp_do_dma(). In particular this involves adding the check to see if the FIFO is at its low threshold since PDMA and mixed DMA and non-DMA requests can leave data remaining in the FIFO. At the same time update all the comments so that they are also consistent between all similar code paths. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> --- hw/scsi/esp.c | 44 +++++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 13 deletions(-)