2 second timeout on read().

This restores the previous DAL behavior for read. It turns out
this is a necessary hack to allow us to abort a pending read
when switching to FW download mode due to a non-responsive
NFC controller.

Change-Id: Ief6f82600bb0603daaa50097a54a5ac42ae0f6b4

2 files changed, 40 insertions, 0 deletions

diff --git a/Linux_x86/phDal4Nfc_i2c.c b/Linux_x86/phDal4Nfc_i2c.c
index 140fc93..72da8e7 100644
--- a/Linux_x86/phDal4Nfc_i2c.c
+++ b/Linux_x86/phDal4Nfc_i2c.c
@@ -191,11 +191,31 @@ int phDal4Nfc_i2c_read(uint8_t * pBuffer, int nNbBytesToRead)
 {
     int ret;
     int numRead = 0;
+    struct timeval tv;
+    fd_set rfds;
 
     DAL_ASSERT_STR(gI2cPortContext.nOpened == 1, "read called but not opened!");
     DAL_DEBUG("_i2c_read() called to read %d bytes", nNbBytesToRead);
 
+    // Read with 2 second timeout, so that the read thread can be aborted
+    // when the pn544 does not respond and we need to switch to FW download
+    // mode. This should be done via a control socket instead.
     while (numRead < nNbBytesToRead) {
+        FD_ZERO(&rfds);
+        FD_SET(gI2cPortContext.nHandle, &rfds);
+        tv.tv_sec = 2;
+        tv.tv_usec = 0;
+        ret = select(gI2cPortContext.nHandle + 1, &rfds, NULL, NULL, &tv);
+        if (ret < 0) {
+            DAL_DEBUG("select() errno=%d", errno);
+            if (errno == EINTR || errno == EAGAIN) {
+                continue;
+            }
+            return -1;
+        } else if (ret == 0) {
+            DAL_PRINT("timeout!");
+            return -1;
+        }
         ret = read(gI2cPortContext.nHandle, pBuffer + numRead, nNbBytesToRead - numRead);
         if (ret > 0) {
             DAL_DEBUG("read %d bytes", ret);
diff --git a/Linux_x86/phDal4Nfc_uart.c b/Linux_x86/phDal4Nfc_uart.c
index b4a282d..7ab4021 100644
--- a/Linux_x86/phDal4Nfc_uart.c
+++ b/Linux_x86/phDal4Nfc_uart.c
@@ -273,11 +273,31 @@ int phDal4Nfc_uart_read(uint8_t * pBuffer, int nNbBytesToRead)
 {
     int ret;
     int numRead = 0;
+    struct timeval tv;
+    fd_set rfds;
 
     DAL_ASSERT_STR(gComPortContext.nOpened == 1, "read called but not opened!");
     DAL_DEBUG("_uart_read() called to read %d bytes", nNbBytesToRead);
 
+    // Read with 2 second timeout, so that the read thread can be aborted
+    // when the pn544 does not respond and we need to switch to FW download
+    // mode. This should be done via a control socket instead.
     while (numRead < nNbBytesToRead) {
+       FD_ZERO(&rfds);
+       FD_SET(gComPortContext.nHandle, &rfds);
+       tv.tv_sec = 2;
+       tv.tv_usec = 0;
+       ret = select(gComPortContext.nHandle + 1, &rfds, NULL, NULL, &tv);
+       if (ret < 0) {
+           DAL_DEBUG("select() errno=%d", errno);
+           if (errno == EINTR || errno == EAGAIN) {
+               continue;
+           }
+           return -1;
+       } else if (ret == 0) {
+           DAL_PRINT("timeout!");
+           return -1;
+       }
        ret = read(gComPortContext.nHandle, pBuffer + numRead, nNbBytesToRead - numRead);
        if (ret > 0) {
            DAL_DEBUG("read %d bytes", ret);