@@ -481,7 +481,6 @@ static void esp_dma_done(ESPState *s)
{
s->rregs[ESP_RSTAT] |= STAT_TC;
s->rregs[ESP_RINTR] |= INTR_BS;
- s->rregs[ESP_RSEQ] = 0;
s->rregs[ESP_RFLAGS] = 0;
esp_set_tc(s, 0);
esp_raise_irq(s);
@@ -917,7 +916,15 @@ uint64_t esp_reg_read(ESPState *s, uint32_t saddr)
val = s->rregs[ESP_RINTR];
s->rregs[ESP_RINTR] = 0;
s->rregs[ESP_RSTAT] &= ~STAT_TC;
- s->rregs[ESP_RSEQ] = SEQ_0;
+ /*
+ * According to the datasheet ESP_RSEQ should be cleared, but as the
+ * emulation currently defers information transfers to the next TI
+ * command leave it for now so that pedantic guests such as the old
+ * Linux 2.6 driver see the correct flags before the next SCSI phase
+ * transition.
+ *
+ * s->rregs[ESP_RSEQ] = SEQ_0;
+ */
esp_lower_irq(s);
break;
case ESP_TCHI:
When processing a command to select a target and send a CDB, the ESP device maintains a sequence step register so that if an error occurs the host can determine which part of the selection/CDB submission sequence failed. The old Linux 2.6 driver is really pedantic here: it checks the sequence step register even if a command succeeds and complains loudly on the console if the sequence step register doesn't match the expected bus phase and interrupt flags. This reason this mismatch occurs is because the ESP emulation currently doesn't update the bus phase until the next TI (Transfer Information) command and so the cleared sequence step register is considered invalid for the stale bus phase. Normally this isn't an issue as the host only checks the sequence step register if an error occurs but the old Linux 2.6 driver does this in several places causing a large stream of "esp0: STEP_ASEL for tgt 0" messages to appear on the console during the boot process. Fix this by not clearing the sequence step register when reading the interrupt register and clearing the DMA status, so the guest sees a valid sequence step and bus phase combination at the end of the command phase. No other change is required since the sequence step register is correctly updated throughout the selection/CDB submission sequence once one of the select commands is issued. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Fixes: 1b9e48a5bd ("esp: implement non-DMA transfers in PDMA mode") --- hw/scsi/esp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)