xhci: Fix incorrect stream context type macro

The stream contex type (SCT) bitfield is used both in the stream context
data structure,  and in the 'Set TR Dequeue pointer' command TRB.
In both cases it uses bits 3:1

The SCT_FOR_TRB(p) macro used to set the stream context type (SCT) field
for the 'Set TR Dequeue pointer' command TRB incorrectly shifts the value
1 bit left before masking the three bits.

Fix this by first masking and rshifting, just like the similar
SCT_FOR_CTX(p) macro does

This issue has not been visibile as the lost bit 3 is only used with
secondary stream arrays (SSA). Xhci driver currently only supports using
a primary stream array with Linear stream addressing.

Fixes: 95241dbdf828 ("xhci: Set SCT field for Set TR dequeue on streams")
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241016140000.783905-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 620502d..f0fb696 100644 (file)
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1001,7 +1001,7 @@ enum xhci_setup_dev {
 /* Set TR Dequeue Pointer command TRB fields, 6.4.3.9 */
 #define TRB_TO_STREAM_ID(p)            ((((p) & (0xffff << 16)) >> 16))
 #define STREAM_ID_FOR_TRB(p)           ((((p)) & 0xffff) << 16)
-#define SCT_FOR_TRB(p)                 (((p) << 1) & 0x7)
+#define SCT_FOR_TRB(p)                 (((p) & 0x7) << 1)
 
 /* Link TRB specific fields */
 #define TRB_TC                 (1<<1)