retry i2c_write when failing with -EIO

cinit · Dec 19, 2021 · 86c7c39 · 86c7c39
1 parent fc09005
commit 86c7c39
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/app/src/main/cpp/libnxphalpatch/ipc/ipc_request_handler.cpp b/app/src/main/cpp/libnxphalpatch/ipc/ipc_request_handler.cpp
@@ -90,6 +90,11 @@ void handleDeviceWriteRequest(uint32_t requestId, const void *payload, uint32_t
         auto size = size_t(requestBody->length);
         if (sNciDeviceFd > 0) {
             ssize_t result = write(fd, data, size);
+            if (result < 0 && errno == EIO) {
+                // NFCC may be in standby mode, wait 5ms and retry once
+                usleep(5000);
+                result = write(fd, data, size);
+            }
             if (result == -1) {
                 result = -errno;
             }