[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PULL 07/45] esp: only set ESP_RSEQ at the start of the select sequence
From: |
Paolo Bonzini |
Subject: |
[PULL 07/45] esp: only set ESP_RSEQ at the start of the select sequence |
Date: |
Thu, 17 Jun 2021 11:30:56 +0200 |
From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
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")
Message-Id: <20210518212511.21688-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/scsi/esp.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
index 000e45a624..18d4d56392 100644
--- a/hw/scsi/esp.c
+++ b/hw/scsi/esp.c
@@ -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:
--
2.31.1
- [PULL 00/45] Memory, i386, compilation, bugfix changes for 2021-06-17, Paolo Bonzini, 2021/06/17
- [PULL 01/45] vnc: avoid deprecation warnings for SASL on OS X, Paolo Bonzini, 2021/06/17
- [PULL 02/45] vl: Fix an assert failure in error path, Paolo Bonzini, 2021/06/17
- [PULL 04/45] block/scsi: correctly emulate the VPD block limits page, Paolo Bonzini, 2021/06/17
- [PULL 03/45] qemu-config: use qemu_opts_from_qdict, Paolo Bonzini, 2021/06/17
- [PULL 08/45] esp: allow non-DMA callback in esp_transfer_data() initial transfer, Paolo Bonzini, 2021/06/17
- [PULL 05/45] runstate: Initialize Error * to NULL, Paolo Bonzini, 2021/06/17
- [PULL 06/45] esp: only assert INTR_DC interrupt flag if selection fails, Paolo Bonzini, 2021/06/17
- [PULL 07/45] esp: only set ESP_RSEQ at the start of the select sequence,
Paolo Bonzini <=
- [PULL 11/45] esp: revert 75ef849696 "esp: correctly fill bus id with requested lun", Paolo Bonzini, 2021/06/17
- [PULL 14/45] esp: store lun coming from the MESSAGE OUT phase, Paolo Bonzini, 2021/06/17
- [PULL 15/45] softmmu/physmem: Mark shared anonymous memory RAM_SHARED, Paolo Bonzini, 2021/06/17
- [PULL 16/45] softmmu/physmem: Fix ram_block_discard_range() to handle shared anonymous memory, Paolo Bonzini, 2021/06/17
- [PULL 18/45] util/mmap-alloc: Factor out calculation of the pagesize for the guard page, Paolo Bonzini, 2021/06/17
- [PULL 09/45] esp: handle non-DMA transfers from the target one byte at a time, Paolo Bonzini, 2021/06/17
- [PULL 10/45] esp: ensure PDMA write transfers are flushed from the FIFO to the target immediately, Paolo Bonzini, 2021/06/17
- [PULL 13/45] esp: fix migration version check in esp_is_version_5(), Paolo Bonzini, 2021/06/17
- [PULL 12/45] esp: correctly accumulate extended messages for PDMA, Paolo Bonzini, 2021/06/17
- [PULL 17/45] softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous memory, Paolo Bonzini, 2021/06/17