usb: xhci: move link chain bit quirk checks into one helper function.

commit 7476a2215c07703db5e95efaa3fc5b9f957b9417 upstream.

Older 0.95 xHCI hosts and some other specific newer hosts require the
chain bit to be set for Link TRBs even if the link TRB is not in the
middle of a transfer descriptor (TD).

move the checks for all those cases  into one xhci_link_chain_quirk()
function to clean up and avoid code duplication.

No functional changes.

[skip renaming chain_links flag, reword commit message -Mathias]

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240626124835.1023046-10-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Shivani: Modified to apply on v5.10.y-v6.1.y]
Signed-off-by: Shivani Agarwal <shivani.agarwal@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index a92bb5a231a8c6410254fd86f0c4923661855a8e..fb81e61a599d755d9634803e87db2f4ab83f82fc 100644 (file)
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -133,10 +133,7 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *ring,
        if (!ring || !first || !last)
                return;
 
-       /* Set chain bit for 0.95 hosts, and for isoc rings on AMD 0.96 host */
-       chain_links = !!(xhci_link_trb_quirk(xhci) ||
-                        (ring->type == TYPE_ISOC &&
-                         (xhci->quirks & XHCI_AMD_0x96_HOST)));
+       chain_links = xhci_link_chain_quirk(xhci, ring->type);
 
        next = ring->enq_seg->next;
        xhci_link_segments(ring->enq_seg, first, ring->type, chain_links);
@@ -326,10 +323,7 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
        struct xhci_segment *prev;
        bool chain_links;
 
-       /* Set chain bit for 0.95 hosts, and for isoc rings on AMD 0.96 host */
-       chain_links = !!(xhci_link_trb_quirk(xhci) ||
-                        (type == TYPE_ISOC &&
-                         (xhci->quirks & XHCI_AMD_0x96_HOST)));
+       chain_links = xhci_link_chain_quirk(xhci, type);
 
        prev = xhci_segment_alloc(xhci, cycle_state, max_packet, flags);
        if (!prev)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 0ff63e9d815aa1d1d9e4ff12d6e69be7374e552c..2d06f54839e0cacb323e7e19051089915c250a16 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -250,9 +250,7 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
                 * AMD 0.96 host, carry over the chain bit of the previous TRB
                 * (which may mean the chain bit is cleared).
                 */
-               if (!(ring->type == TYPE_ISOC &&
-                     (xhci->quirks & XHCI_AMD_0x96_HOST)) &&
-                   !xhci_link_trb_quirk(xhci)) {
+               if (!xhci_link_chain_quirk(xhci, ring->type)) {
                        next->link.control &= cpu_to_le32(~TRB_CHAIN);
                        next->link.control |= cpu_to_le32(chain);
                }
@@ -3425,9 +3423,7 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
                /* If we're not dealing with 0.95 hardware or isoc rings
                 * on AMD 0.96 host, clear the chain bit.
                 */
-               if (!xhci_link_trb_quirk(xhci) &&
-                   !(ep_ring->type == TYPE_ISOC &&
-                     (xhci->quirks & XHCI_AMD_0x96_HOST)))
+               if (!xhci_link_chain_quirk(xhci, ep_ring->type))
                        ep_ring->enqueue->link.control &=
                                cpu_to_le32(~TRB_CHAIN);
                else

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 22a5fcea36de3aac116d2c96390b296b67a7f167..6ce3005533fb3aab2f88fa572a134b974694377b 100644 (file)
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1768,9 +1768,12 @@ static inline void xhci_write_64(struct xhci_hcd *xhci,
        lo_hi_writeq(val, regs);
 }
 
-static inline int xhci_link_trb_quirk(struct xhci_hcd *xhci)
+
+/* Link TRB chain should always be set on 0.95 hosts, and AMD 0.96 ISOC rings */
+static inline bool xhci_link_chain_quirk(struct xhci_hcd *xhci, enum xhci_ring_type type)
 {
-       return xhci->quirks & XHCI_LINK_TRB_QUIRK;
+       return (xhci->quirks & XHCI_LINK_TRB_QUIRK) ||
+              (type == TYPE_ISOC && (xhci->quirks & XHCI_AMD_0x96_HOST));
 }
 
 /* xHCI debugging */