[RFC PATCH 10/13] powerpc/vas: Do not use default credits for receive window

[Haren Myneni]

System checkstops if RxFIFO overruns with more requests than the
maximum possible number of CRBs allowed in FIFO at any time. So
max credits value (rxattr.wcreds_max) is set and is passed to
vas_rx_win_open() by the the driver.

Signed-off-by:Haren Myneni <ha...@us.ibm.com>
---
 arch/powerpc/platforms/powernv/vas-window.c | 4 ++--
 arch/powerpc/platforms/powernv/vas.h        | 2 --
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/vas-window.c 
b/arch/powerpc/platforms/powernv/vas-window.c
index 2946dd6..9d32d97 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -779,7 +779,7 @@ static bool rx_win_args_valid(enum vas_cop_type cop,
        if (attr->rx_fifo_size > VAS_RX_FIFO_SIZE_MAX)
                return false;
 
-       if (attr->wcreds_max > VAS_RX_WCREDS_MAX)
+       if (!attr->wcreds_max)
                return false;
 
        if (attr->nx_win) {
@@ -885,7 +885,7 @@ struct vas_window *vas_rx_win_open(int vasid, enum 
vas_cop_type cop,
        rxwin->nx_win = rxattr->nx_win;
        rxwin->user_win = rxattr->user_win;
        rxwin->cop = cop;
-       rxwin->wcreds_max = rxattr->wcreds_max ?: VAS_WCREDS_DEFAULT;
+       rxwin->wcreds_max = rxattr->wcreds_max;
        if (rxattr->user_win) {
                rxwin->pid = task_pid_vnr(current);
                rxwin->tgid = task_tgid_vnr(current);
diff --git a/arch/powerpc/platforms/powernv/vas.h 
b/arch/powerpc/platforms/powernv/vas.h
index 1812c59..d1e32a0 100644
--- a/arch/powerpc/platforms/powernv/vas.h
+++ b/arch/powerpc/platforms/powernv/vas.h
@@ -101,11 +101,9 @@
 /*
  * Initial per-process credits.
  * Max send window credits:    4K-1 (12-bits in VAS_TX_WCRED)
- * Max receive window credits: 64K-1 (16 bits in VAS_LRX_WCRED)
  *
  * TODO: Needs tuning for per-process credits
  */
-#define VAS_RX_WCREDS_MAX              ((64 << 10) - 1)
 #define VAS_TX_WCREDS_MAX              ((4 << 10) - 1)
 #define VAS_WCREDS_DEFAULT             (1 << 10)
 
-- 
1.8.3.1