i2cdetect: fix address skipping in auto mode

If the bus doesn't support SMBus Quick Write or Receive Byte commands
and we're running in auto mode all addresses will be skipped resulting
in an empty table being printed.

This is caused by not restoring the auto mode after it's been changed
for certain address ranges - we need an additional variable to hold the
temporary state.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
index d77e6bacf51876626f92bc60824f71d2db9ea3df..c5baaa78ec817563c4dd1913427694939f2b2b46 100644 (file)
--- a/miscutils/i2c_tools.c
+++ b/miscutils/i2c_tools.c
@@ -1200,7 +1200,7 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
                              opt_F = (1 << 4), opt_l = (1 << 5);
        const char *const optstr = "yaqrFl";
 
-       int fd, bus_num, i, j, mode = I2CDETECT_MODE_AUTO, status;
+       int fd, bus_num, i, j, mode = I2CDETECT_MODE_AUTO, status, cmd;
        unsigned first = 0x03, last = 0x77, opts;
        unsigned long funcs;
 
@@ -1273,19 +1273,20 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
                for(j = 0; j < 16; j++) {
                        fflush_all();
 
+                       cmd = mode;
                        if (mode == I2CDETECT_MODE_AUTO) {
                                if ((i+j >= 0x30 && i+j <= 0x37) ||
                                    (i+j >= 0x50 && i+j <= 0x5F))
-                                       mode = I2CDETECT_MODE_READ;
+                                       cmd = I2CDETECT_MODE_READ;
                                else
-                                       mode = I2CDETECT_MODE_QUICK;
+                                       cmd = I2CDETECT_MODE_QUICK;
                        }
 
                        /* Skip unwanted addresses. */
                        if (i+j < first
                         || i+j > last
-                        || (mode == I2CDETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE))
-                        || (mode == I2CDETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)))
+                        || (cmd == I2CDETECT_MODE_READ && !(funcs & I2C_FUNC_SMBUS_READ_BYTE))
+                        || (cmd == I2CDETECT_MODE_QUICK && !(funcs & I2C_FUNC_SMBUS_QUICK)))
                        {
                                printf("   ");
                                continue;
@@ -1302,7 +1303,7 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
                                        "can't set address to 0x%02x", i + j);
                        }
 
-                       switch (mode) {
+                       switch (cmd) {
                        case I2CDETECT_MODE_READ:
                                /*
                                 * This is known to lock SMBus on various