From: anonym <ano...@riseup.net>
While formatting partitions (on virtual USB drives and the nec-xhci
virtual USB controller) to EXT4, I have observed errors like these:
kernel: sd 8:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ABORT
driverbyte=DRIVER_OK
kernel: sd 8:0:0:0: [sda] tag#0 CDB: Write(10) 2a 00 00 66 49 86
00 08 00 00
kernel: blk_update_request: I/O error, dev sda, sector 6703494
kernel: Buffer I/O error on dev dm-0, logical block 1573254, lost
async page write
Raising TRB_LINK_LIMIT fixes the limit, but the new value was
admittedly arbitrarily chosen.
Regarding cycle detection in general, allowing at most 4 levels of
links seems pretty low. This bump should be safe: a high number only
means that we get a performance hit when encountering cycles but then
we should have a fatal error any way; a low number instead means that
we'll incorrectly identify cycles and abort operations that otherwise
would succeed, like in the case above.
Signed-off-by: anonym <ano...@riseup.net>
---
hw/usb/hcd-xhci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 4acf0c6dd8..d14ce126a2 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -53,7 +53,7 @@
* to the specs when it gets them */
#define ER_FULL_HACK
-#define TRB_LINK_LIMIT 4
+#define TRB_LINK_LIMIT 32
#define LEN_CAP 0x40
#define LEN_OPER (0x400 + 0x10 * MAXPORTS)
--
2.11.0
