rapidio:powerpc/85xx: modify RIO port-write interrupt handler

- Rearrange RIO port-write interrupt handling to perform message
  buffering as soon as possible.

- Modify to disable port-write controller when clearing Transaction
  Error (TE) bit.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 39 insertions, 29 deletions

diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index 412763672d23..ed2ec7154917 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -87,6 +87,9 @@
 #define RIO_IPWSR_PWD           0x00000008
 #define RIO_IPWSR_PWB           0x00000004
 
+#define RIO_EPWISR_PINT         0x80000000
+#define RIO_EPWISR_PW           0x00000001
+
 #define RIO_MSG_DESC_SIZE       32
 #define RIO_MSG_BUFFER_SIZE     4096
 #define RIO_MIN_TX_RING_SIZE    2
@@ -1082,18 +1085,12 @@ fsl_rio_port_write_handler(int irq, void *dev_instance)
         struct rio_priv *priv = port->priv;
         u32 epwisr, tmp;
 
-        ipwmr = in_be32(&priv->msg_regs->pwmr);
-        ipwsr = in_be32(&priv->msg_regs->pwsr);
-
         epwisr = in_be32(priv->regs_win + RIO_EPWISR);
-        if (epwisr & 0x80000000) {
-                tmp = in_be32(priv->regs_win + RIO_LTLEDCSR);
-                pr_info("RIO_LTLEDCSR = 0x%x\n", tmp);
-                out_be32(priv->regs_win + RIO_LTLEDCSR, 0);
-        }
+        if (!(epwisr & RIO_EPWISR_PW))
+                goto pw_done;
 
-        if (!(epwisr & 0x00000001))
-                return IRQ_HANDLED;
+        ipwmr = in_be32(&priv->msg_regs->pwmr);
+        ipwsr = in_be32(&priv->msg_regs->pwsr);
 
 #ifdef DEBUG_PW
         pr_debug("PW Int->IPWMR: 0x%08x IPWSR: 0x%08x (", ipwmr, ipwsr);
@@ -1109,20 +1106,6 @@ fsl_rio_port_write_handler(int irq, void *dev_instance)
                 pr_debug(" PWB");
         pr_debug(" )\n");
 #endif
-        out_be32(&priv->msg_regs->pwsr,
-                 ipwsr & (RIO_IPWSR_TE | RIO_IPWSR_QFI | RIO_IPWSR_PWD));
-
-        if ((ipwmr & RIO_IPWMR_EIE) && (ipwsr & RIO_IPWSR_TE)) {
-                priv->port_write_msg.err_count++;
-                pr_info("RIO: Port-Write Transaction Err (%d)\n",
-                         priv->port_write_msg.err_count);
-        }
-        if (ipwsr & RIO_IPWSR_PWD) {
-                priv->port_write_msg.discard_count++;
-                pr_info("RIO: Port Discarded Port-Write Msg(s) (%d)\n",
-                         priv->port_write_msg.discard_count);
-        }
-
         /* Schedule deferred processing if PW was received */
         if (ipwsr & RIO_IPWSR_QFI) {
                 /* Save PW message (if there is room in FIFO),
@@ -1134,16 +1117,43 @@ fsl_rio_port_write_handler(int irq, void *dev_instance)
                                  RIO_PW_MSG_SIZE);
                 } else {
                         priv->port_write_msg.discard_count++;
-                        pr_info("RIO: ISR Discarded Port-Write Msg(s) (%d)\n",
+                        pr_debug("RIO: ISR Discarded Port-Write Msg(s) (%d)\n",
                                  priv->port_write_msg.discard_count);
                 }
+                /* Clear interrupt and issue Clear Queue command. This allows
+                 * another port-write to be received.
+                 */
+                out_be32(&priv->msg_regs->pwsr, RIO_IPWSR_QFI);
+                out_be32(&priv->msg_regs->pwmr, ipwmr | RIO_IPWMR_CQ);
+
                 schedule_work(&priv->pw_work);
         }
 
-        /* Issue Clear Queue command. This allows another
-         * port-write to be received.
-         */
-        out_be32(&priv->msg_regs->pwmr, ipwmr | RIO_IPWMR_CQ);
+        if ((ipwmr & RIO_IPWMR_EIE) && (ipwsr & RIO_IPWSR_TE)) {
+                priv->port_write_msg.err_count++;
+                pr_debug("RIO: Port-Write Transaction Err (%d)\n",
+                         priv->port_write_msg.err_count);
+                /* Clear Transaction Error: port-write controller should be
+                 * disabled when clearing this error
+                 */
+                out_be32(&priv->msg_regs->pwmr, ipwmr & ~RIO_IPWMR_PWE);
+                out_be32(&priv->msg_regs->pwsr, RIO_IPWSR_TE);
+                out_be32(&priv->msg_regs->pwmr, ipwmr);
+        }
+
+        if (ipwsr & RIO_IPWSR_PWD) {
+                priv->port_write_msg.discard_count++;
+                pr_debug("RIO: Port Discarded Port-Write Msg(s) (%d)\n",
+                         priv->port_write_msg.discard_count);
+                out_be32(&priv->msg_regs->pwsr, RIO_IPWSR_PWD);
+        }
+
+pw_done:
+        if (epwisr & RIO_EPWISR_PINT) {
+                tmp = in_be32(priv->regs_win + RIO_LTLEDCSR);
+                pr_debug("RIO_LTLEDCSR = 0x%x\n", tmp);
+                out_be32(priv->regs_win + RIO_LTLEDCSR, 0);
+        }
 
         return IRQ_HANDLED;
 }