[SeaBIOS] [PATCH 2/2] uhci: Increase bulk transfer STACKTDS to 16

Kevin O'Connor kevin at koconnor.net
Wed Dec 31 17:32:13 CET 2014

Increase the number of simultaneous transfer descriptors that the
driver will build for uhci.  The old value of 4 was a leftover from
when SeaBIOS had a tiny 512 byte extra stack - now that there is a 2K
extra stack there is plenty of space for additional descriptors.
Using a value of 16 should allow for an entire 1ms frame of bulk
transfer content to be setup in advance (assuming the max packet size
is 64 bytes).

Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
 src/hw/usb-uhci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hw/usb-uhci.c b/src/hw/usb-uhci.c
index 7ef50d1..4eea979 100644
--- a/src/hw/usb-uhci.c
+++ b/src/hw/usb-uhci.c
@@ -500,7 +500,7 @@ uhci_send_control(struct usb_pipe *p, int dir, const void *cmd, int cmdsize
     return ret;
-#define STACKTDS 4
+#define STACKTDS 16
 #define TDALIGN 16

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