[ARM] 4295/2: Fix error-handling in pxaficp_ir.c (version 2)

This patch addresses the following issues with the pxa2xx FIr driver:

1. increment overrun error counter and not frame error counter on ICSR1_ROR bit set in ICSR1.
2. drop frames reported with the frame error from the IC.
3. when resetting the receiver and preparing it for the next DMA in pxa_irda_fir_irq() actually clear the Rx FIFO. See description in Table 11-2 in PXA270 Developer's Manual of the RXE bit.

Correction added in version 2: clearing the IC Rx FIFO also has to be done in pxa_irda_fir_dma_tx_irq()

Signed-off-by: G. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 25 insertions, 5 deletions

diff --git a/drivers/net/irda/pxaficp_ir.c b/drivers/net/irda/pxaficp_ir.c
index 9137e239fac2..2272156af31e 100644
--- a/drivers/net/irda/pxaficp_ir.c
+++ b/drivers/net/irda/pxaficp_ir.c
@@ -321,15 +321,22 @@ static void pxa_irda_fir_dma_tx_irq(int channel, void *data)
                 pxa_irda_set_speed(si, si->newspeed);
                 si->newspeed = 0;
         } else {
+                int i = 64;
+
                 ICCR0 = 0;
                 pxa_irda_fir_dma_rx_start(si);
+                while ((ICSR1 & ICSR1_RNE) && i--)
+                        (void)ICDR;
                 ICCR0 = ICCR0_ITR | ICCR0_RXE;
+
+                if (i < 0)
+                        printk(KERN_ERR "pxa_ir: cannot clear Rx FIFO!\n");
         }
         netif_wake_queue(dev);
 }
 
 /* EIF(Error in FIFO/End in Frame) handler for FIR */
-static void pxa_irda_fir_irq_eif(struct pxa_irda *si, struct net_device *dev)
+static void pxa_irda_fir_irq_eif(struct pxa_irda *si, struct net_device *dev, int icsr0)
 {
         unsigned int len, stat, data;
 
@@ -350,7 +357,7 @@ static void pxa_irda_fir_irq_eif(struct pxa_irda *si, struct net_device *dev)
                         }
                         if (stat & ICSR1_ROR) {
                                 printk(KERN_DEBUG "pxa_ir: fir receive overrun\n");
-                                si->stats.rx_frame_errors++;
+                                si->stats.rx_over_errors++;
                         }
                 } else  {
                         si->dma_rx_buff[len++] = data;
@@ -362,7 +369,15 @@ static void pxa_irda_fir_irq_eif(struct pxa_irda *si, struct net_device *dev)
 
         if (stat & ICSR1_EOF) {
                 /* end of frame. */
-                struct sk_buff *skb = alloc_skb(len+1,GFP_ATOMIC);
+                struct sk_buff *skb;
+
+                if (icsr0 & ICSR0_FRE) {
+                        printk(KERN_ERR "pxa_ir: dropping erroneous frame\n");
+                        si->stats.rx_dropped++;
+                        return;
+                }
+
+                skb = alloc_skb(len+1,GFP_ATOMIC);
                 if (!skb)  {
                         printk(KERN_ERR "pxa_ir: fir out of memory for receive skb\n");
                         si->stats.rx_dropped++;
@@ -392,7 +407,7 @@ static irqreturn_t pxa_irda_fir_irq(int irq, void *dev_id)
 {
         struct net_device *dev = dev_id;
         struct pxa_irda *si = netdev_priv(dev);
-        int icsr0;
+        int icsr0, i = 64;
 
         /* stop RX DMA */
         DCSR(si->rxdma) &= ~DCSR_RUN;
@@ -412,13 +427,18 @@ static irqreturn_t pxa_irda_fir_irq(int irq, void *dev_id)
 
         if (icsr0 & ICSR0_EIF) {
                 /* An error in FIFO occured, or there is a end of frame */
-                pxa_irda_fir_irq_eif(si, dev);
+                pxa_irda_fir_irq_eif(si, dev, icsr0);
         }
 
         ICCR0 = 0;
         pxa_irda_fir_dma_rx_start(si);
+        while ((ICSR1 & ICSR1_RNE) && i--)
+                (void)ICDR;
         ICCR0 = ICCR0_ITR | ICCR0_RXE;
 
+        if (i < 0)
+                printk(KERN_ERR "pxa_ir: cannot clear Rx FIFO!\n");
+
         return IRQ_HANDLED;
 }