The default ones should be find but this allows the user to tweak the
credits to get more performance out of the P2P connection.
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/thunderbolt/tunnel.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index dd3b5613ad2c..3bf2628a5dcd 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -41,9 +41,14 @@
* Number of credits we try to allocate for each DMA path if not limited
* by the host router baMaxHI.
*/
-#define TB_DMA_CREDITS 14U
+#define TB_DMA_CREDITS 14
/* Minimum number of credits for DMA path */
-#define TB_MIN_DMA_CREDITS 1U
+#define TB_MIN_DMA_CREDITS 1
+
+static unsigned int dma_credits = TB_DMA_CREDITS;
+module_param(dma_credits, uint, 0444);
+MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
+ __MODULE_STRING(TB_DMA_CREDITS) ")");
static bool bw_alloc_mode = true;
module_param(bw_alloc_mode, bool, 0444);
@@ -95,7 +100,7 @@ static unsigned int tb_available_credits(const struct tb_port *port,
pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
if (tb_acpi_is_xdomain_allowed()) {
- spare = min_not_zero(sw->max_dma_credits, TB_DMA_CREDITS);
+ spare = min_not_zero(sw->max_dma_credits, dma_credits);
/* Add some credits for potential second DMA tunnel */
spare += TB_MIN_DMA_CREDITS;
} else {
@@ -1472,7 +1477,7 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
tunnel->dst_port = dst;
tunnel->deinit = tb_dma_deinit;
- credits = min_not_zero(TB_DMA_CREDITS, nhi->sw->max_dma_credits);
+ credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
if (receive_ring > 0) {
path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
--
2.39.2
