diff mbox series

[RFC,13/13] dp8393x: fix receiving buffer exhaustion

Message ID 20180608200558.386-14-laurent@vivier.eu
State New
Headers show
Series hw/m68k: add Apple Machintosh Quadra 800 machine | expand

Commit Message

Laurent Vivier June 8, 2018, 8:05 p.m. UTC 
The card is not able to exit from exhaustion state, because
while the drive consumes the buffers, the RRP is incremented
(when the driver clears the ISR RBE bit), so it stays equal
to RWP, and while RRP == RWP, the card thinks it is always
in exhaustion state. So the driver consumes all the buffers,
but the card cannot receive new ones.

This patch fixes the problem by not incrementing RRP when
the driver clears the ISR RBE bit.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 hw/net/dp8393x.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

Comments

Hervé Poussineau June 9, 2018, 8:55 a.m. UTC | #1 
Le 08/06/2018 à 22:05, Laurent Vivier a écrit :
> The card is not able to exit from exhaustion state, because
> while the drive consumes the buffers, the RRP is incremented
> (when the driver clears the ISR RBE bit), so it stays equal
> to RWP, and while RRP == RWP, the card thinks it is always
> in exhaustion state. So the driver consumes all the buffers,
> but the card cannot receive new ones.
> 
> This patch fixes the problem by not incrementing RRP when
> the driver clears the ISR RBE bit.
> 
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>   hw/net/dp8393x.c | 31 ++++++++++++++++---------------
>   1 file changed, 16 insertions(+), 15 deletions(-)
> 

Works OK on NetBSD 5.1/arc on MIPS Magnum.

Tested-by: Hervé Poussineau <hpoussin@reactos.org>
diff mbox series

Patch

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 40e5f8257b..fd0f6cf2a0 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -314,7 +314,7 @@  static void dp8393x_do_load_cam(dp8393xState *s)
     dp8393x_update_irq(s);
 }
 
-static void dp8393x_do_read_rra(dp8393xState *s)
+static void dp8393x_do_read_rra(dp8393xState *s, int next)
 {
     int width, size;
 
@@ -333,19 +333,20 @@  static void dp8393x_do_read_rra(dp8393xState *s)
         s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
         s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
 
-    /* Go to next entry */
-    s->regs[SONIC_RRP] += size;
+    if (next) {
+        /* Go to next entry */
+        s->regs[SONIC_RRP] += size;
 
-    /* Handle wrap */
-    if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
-        s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
-    }
+        /* Handle wrap */
+        if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
+            s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
+        }
 
-    /* Check resource exhaustion */
-    if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP])
-    {
-        s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
-        dp8393x_update_irq(s);
+        /* Check resource exhaustion */
+        if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP]) {
+            s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
+            dp8393x_update_irq(s);
+        }
     }
 
     /* Done */
@@ -559,7 +560,7 @@  static void dp8393x_do_command(dp8393xState *s, uint16_t command)
     if (command & SONIC_CR_RST)
         dp8393x_do_software_reset(s);
     if (command & SONIC_CR_RRRA)
-        dp8393x_do_read_rra(s);
+        dp8393x_do_read_rra(s, 1);
     if (command & SONIC_CR_LCAM)
         dp8393x_do_load_cam(s);
 }
@@ -650,7 +651,7 @@  static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
             data &= s->regs[reg];
             s->regs[reg] &= ~data;
             if (data & SONIC_ISR_RBE) {
-                dp8393x_do_read_rra(s);
+                dp8393x_do_read_rra(s, 0);
             }
             dp8393x_update_irq(s);
             if (dp8393x_can_receive(s->nic->ncs)) {
@@ -852,7 +853,7 @@  static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
 
         if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
             /* Read next RRA */
-            dp8393x_do_read_rra(s);
+            dp8393x_do_read_rra(s, 1);
         }
     }