caif: SPI-driver bugfix - incorrect padding.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 53 insertions, 19 deletions

diff --git a/drivers/net/caif/caif_spi.c b/drivers/net/caif/caif_spi.c
index 8427533fe313..8b4cea57a6c5 100644
--- a/drivers/net/caif/caif_spi.c
+++ b/drivers/net/caif/caif_spi.c
@@ -33,6 +33,9 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
 MODULE_DESCRIPTION("CAIF SPI driver");
 
+/* Returns the number of padding bytes for alignment. */
+#define PAD_POW2(x, pow) ((((x)&((pow)-1))==0) ? 0 : (((pow)-((x)&((pow)-1)))))
+
 static int spi_loop;
 module_param(spi_loop, bool, S_IRUGO);
 MODULE_PARM_DESC(spi_loop, "SPI running in loopback mode.");
@@ -41,7 +44,10 @@ MODULE_PARM_DESC(spi_loop, "SPI running in loopback mode.");
 module_param(spi_frm_align, int, S_IRUGO);
 MODULE_PARM_DESC(spi_frm_align, "SPI frame alignment.");
 
-/* SPI padding options. */
+/*
+ * SPI padding options.
+ * Warning: must be a base of 2 (& operation used) and can not be zero !
+ */
 module_param(spi_up_head_align, int, S_IRUGO);
 MODULE_PARM_DESC(spi_up_head_align, "SPI uplink head alignment.");
 
@@ -240,15 +246,13 @@ static ssize_t dbgfs_frame(struct file *file, char __user *user_buf,
 static const struct file_operations dbgfs_state_fops = {
         .open = dbgfs_open,
         .read = dbgfs_state,
-        .owner = THIS_MODULE,
-        .llseek = default_llseek,
+        .owner = THIS_MODULE
 };
 
 static const struct file_operations dbgfs_frame_fops = {
         .open = dbgfs_open,
         .read = dbgfs_frame,
-        .owner = THIS_MODULE,
-        .llseek = default_llseek,
+        .owner = THIS_MODULE
 };
 
 static inline void dev_debugfs_add(struct cfspi *cfspi)
@@ -337,6 +341,9 @@ int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
         u8 *dst = buf;
         caif_assert(buf);
 
+        if (cfspi->slave && !cfspi->slave_talked)
+                cfspi->slave_talked = true;
+
         do {
                 struct sk_buff *skb;
                 struct caif_payload_info *info;
@@ -357,8 +364,8 @@ int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
                  * Compute head offset i.e. number of bytes to add to
                  * get the start of the payload aligned.
                  */
-                if (spi_up_head_align) {
-                        spad = 1 + ((info->hdr_len + 1) & spi_up_head_align);
+                if (spi_up_head_align > 1) {
+                        spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
                         *dst = (u8)(spad - 1);
                         dst += spad;
                 }
@@ -373,7 +380,7 @@ int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
                  * Compute tail offset i.e. number of bytes to add to
                  * get the complete CAIF frame aligned.
                  */
-                epad = (skb->len + spad) & spi_up_tail_align;
+                epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
                 dst += epad;
 
                 dev_kfree_skb(skb);
@@ -417,14 +424,14 @@ int cfspi_xmitlen(struct cfspi *cfspi)
                  * Compute head offset i.e. number of bytes to add to
                  * get the start of the payload aligned.
                  */
-                if (spi_up_head_align)
-                        spad = 1 + ((info->hdr_len + 1) & spi_up_head_align);
+                if (spi_up_head_align > 1)
+                        spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
 
                 /*
                  * Compute tail offset i.e. number of bytes to add to
                  * get the complete CAIF frame aligned.
                  */
-                epad = (skb->len + spad) & spi_up_tail_align;
+                epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
 
                 if ((skb->len + spad + epad + frm_len) <= CAIF_MAX_SPI_FRAME) {
                         skb_queue_tail(&cfspi->chead, skb);
@@ -433,6 +440,7 @@ int cfspi_xmitlen(struct cfspi *cfspi)
                 } else {
                         /* Put back packet. */
                         skb_queue_head(&cfspi->qhead, skb);
+                        break;
                 }
         } while (pkts <= CAIF_MAX_SPI_PKTS);
 
@@ -453,6 +461,15 @@ static void cfspi_ss_cb(bool assert, struct cfspi_ifc *ifc)
 {
         struct cfspi *cfspi = (struct cfspi *)ifc->priv;
 
+        /*
+         * The slave device is the master on the link. Interrupts before the
+         * slave has transmitted are considered spurious.
+         */
+        if (cfspi->slave && !cfspi->slave_talked) {
+                printk(KERN_WARNING "CFSPI: Spurious SS interrupt.\n");
+                return;
+        }
+
         if (!in_interrupt())
                 spin_lock(&cfspi->lock);
         if (assert) {
@@ -465,7 +482,8 @@ static void cfspi_ss_cb(bool assert, struct cfspi_ifc *ifc)
                 spin_unlock(&cfspi->lock);
 
         /* Wake up the xfer thread. */
-        wake_up_interruptible(&cfspi->wait);
+        if (assert)
+                wake_up_interruptible(&cfspi->wait);
 }
 
 static void cfspi_xfer_done_cb(struct cfspi_ifc *ifc)
@@ -523,7 +541,7 @@ int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
                  * Compute head offset i.e. number of bytes added to
                  * get the start of the payload aligned.
                  */
-                if (spi_down_head_align) {
+                if (spi_down_head_align > 1) {
                         spad = 1 + *src;
                         src += spad;
                 }
@@ -564,7 +582,7 @@ int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
                  * Compute tail offset i.e. number of bytes added to
                  * get the complete CAIF frame aligned.
                  */
-                epad = (pkt_len + spad) & spi_down_tail_align;
+                epad = PAD_POW2((pkt_len + spad), spi_down_tail_align);
                 src += epad;
         } while ((src - buf) < len);
 
@@ -625,11 +643,20 @@ int cfspi_spi_probe(struct platform_device *pdev)
         cfspi->ndev = ndev;
         cfspi->pdev = pdev;
 
-        /* Set flow info */
+        /* Set flow info. */
         cfspi->flow_off_sent = 0;
         cfspi->qd_low_mark = LOW_WATER_MARK;
         cfspi->qd_high_mark = HIGH_WATER_MARK;
 
+        /* Set slave info. */
+        if (!strncmp(cfspi_spi_driver.driver.name, "cfspi_sspi", 10)) {
+                cfspi->slave = true;
+                cfspi->slave_talked = false;
+        } else {
+                cfspi->slave = false;
+                cfspi->slave_talked = false;
+        }
+
         /* Assign the SPI device. */
         cfspi->dev = dev;
         /* Assign the device ifc to this SPI interface. */
diff --git a/drivers/net/caif/caif_spi_slave.c b/drivers/net/caif/caif_spi_slave.c
index 2111dbfea6fe..1b9943a4edab 100644
--- a/drivers/net/caif/caif_spi_slave.c
+++ b/drivers/net/caif/caif_spi_slave.c
@@ -36,10 +36,15 @@ static inline int forward_to_spi_cmd(struct cfspi *cfspi)
 #endif
 
 int spi_frm_align = 2;
-int spi_up_head_align = 1;
-int spi_up_tail_align;
-int spi_down_head_align = 3;
-int spi_down_tail_align = 1;
+
+/*
+ * SPI padding options.
+ * Warning: must be a base of 2 (& operation used) and can not be zero !
+ */
+int spi_up_head_align   = 1 << 1;
+int spi_up_tail_align   = 1 << 0;
+int spi_down_head_align = 1 << 2;
+int spi_down_tail_align = 1 << 1;
 
 #ifdef CONFIG_DEBUG_FS
 static inline void debugfs_store_prev(struct cfspi *cfspi)
diff --git a/include/net/caif/caif_spi.h b/include/net/caif/caif_spi.h
index ce4570dff020..87c3d11b8e55 100644
--- a/include/net/caif/caif_spi.h
+++ b/include/net/caif/caif_spi.h
@@ -121,6 +121,8 @@ struct cfspi {
         wait_queue_head_t wait;
         spinlock_t lock;
         bool flow_stop;
+        bool slave;
+        bool slave_talked;
 #ifdef CONFIG_DEBUG_FS
         enum cfspi_state dbg_state;
         u16 pcmd;