Re: [U-Boot] unused-const-variable warnings in FSL DDR driver

27 Mar 2017

...
From: york sun [mailto:york.sun@nxp.com] 
Sent: Samstag, 25. März 2017 16:35
To: Thomas Schaefer; Tom Rini
Cc: u-boot@lists.denx.de
Re: Re: AW: [U-Boot] unused-const-variable warnings in FSL DDR driver
Thomas,
Can you put your patch together with proper commit message and signature? I prefer your solution than this one http://patchwork.ozlabs.org/patch/726353/
York
Hi York,
please find the patch in the attachment.
Best regards,
Thomas
commit 66dcf316bf2649e576f1b79aad3a5bb950d178d6
Author: Thomas Schaefer thomas.schaefer@kontron.com
Date:   Mon Mar 27 10:17:09 2017 +0200
drivers: ddr: fix unused-const-variable warnings
Depending on DDR configuration, gcc-6.x will show up unused-const-
    variable messages. Use __maybe_unused specifier for all dynamic_odt
    variable definitions to remove these warnings.
Memory footprint will not increase as gcc will optimize out unused
    constants.
Signed-off-by: Thomas Schaefer thomas.schaefer@kontron.com

diff --git a/drivers/ddr/fsl/options.c b/drivers/ddr/fsl/options.c
index d6a8fcb216..64aaa77047 100644
--- a/drivers/ddr/fsl/options.c
+++ b/drivers/ddr/fsl/options.c
@@ -33,7 +33,7 @@ struct dynamic_odt {
 /* Quad rank is not verified yet due availability.
  * Replacing 20 OHM with 34 OHM since DDR4 doesn't have 20 OHM option
  */
-static const struct dynamic_odt single_Q[4] = {
+__maybe_unused static const struct dynamic_odt single_Q[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS_AND_OTHER_DIMM,
@@ -60,7 +60,7 @@ static const struct dynamic_odt single_Q[4] = {
        }
 };
-static const struct dynamic_odt single_D[4] = {
+__maybe_unused static const struct dynamic_odt single_D[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -77,7 +77,7 @@ static const struct dynamic_odt single_D[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt single_S[4] = {
+__maybe_unused static const struct dynamic_odt single_S[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -89,7 +89,7 @@ static const struct dynamic_odt single_S[4] = {
        {0, 0, 0, 0},
 };
-static const struct dynamic_odt dual_DD[4] = {
+__maybe_unused static const struct dynamic_odt dual_DD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -116,7 +116,7 @@ static const struct dynamic_odt dual_DD[4] = {
        }
 };
-static const struct dynamic_odt dual_DS[4] = {
+__maybe_unused static const struct dynamic_odt dual_DS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -137,7 +137,7 @@ static const struct dynamic_odt dual_DS[4] = {
        },
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_SD[4] = {
+__maybe_unused static const struct dynamic_odt dual_SD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_ALL,
@@ -159,7 +159,7 @@ static const struct dynamic_odt dual_SD[4] = {
        }
 };
-static const struct dynamic_odt dual_SS[4] = {
+__maybe_unused static const struct dynamic_odt dual_SS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_ALL,
@@ -176,7 +176,7 @@ static const struct dynamic_odt dual_SS[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_D0[4] = {
+__maybe_unused static const struct dynamic_odt dual_D0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -193,7 +193,7 @@ static const struct dynamic_odt dual_D0[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_0D[4] = {
+__maybe_unused static const struct dynamic_odt dual_0D[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -210,7 +210,7 @@ static const struct dynamic_odt dual_0D[4] = {
        }
 };
-static const struct dynamic_odt dual_S0[4] = {
+__maybe_unused static const struct dynamic_odt dual_S0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,
@@ -223,7 +223,7 @@ static const struct dynamic_odt dual_S0[4] = {
};
-static const struct dynamic_odt dual_0S[4] = {
+__maybe_unused static const struct dynamic_odt dual_0S[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -236,7 +236,7 @@ static const struct dynamic_odt dual_0S[4] = {
};
-static const struct dynamic_odt odt_unknown[4] = {
+__maybe_unused static const struct dynamic_odt odt_unknown[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,
@@ -263,7 +263,7 @@ static const struct dynamic_odt odt_unknown[4] = {
        }
 };
 #elif defined(CONFIG_SYS_FSL_DDR3)
-static const struct dynamic_odt single_Q[4] = {
+__maybe_unused static const struct dynamic_odt single_Q[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS_AND_OTHER_DIMM,
@@ -290,7 +290,7 @@ static const struct dynamic_odt single_Q[4] = {
        }
 };
-static const struct dynamic_odt single_D[4] = {
+__maybe_unused static const struct dynamic_odt single_D[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -307,7 +307,7 @@ static const struct dynamic_odt single_D[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt single_S[4] = {
+__maybe_unused static const struct dynamic_odt single_S[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -319,7 +319,7 @@ static const struct dynamic_odt single_S[4] = {
        {0, 0, 0, 0},
 };
-static const struct dynamic_odt dual_DD[4] = {
+__maybe_unused static const struct dynamic_odt dual_DD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -346,7 +346,7 @@ static const struct dynamic_odt dual_DD[4] = {
        }
 };
-static const struct dynamic_odt dual_DS[4] = {
+__maybe_unused static const struct dynamic_odt dual_DS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -367,7 +367,7 @@ static const struct dynamic_odt dual_DS[4] = {
        },
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_SD[4] = {
+__maybe_unused static const struct dynamic_odt dual_SD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_ALL,
@@ -389,7 +389,7 @@ static const struct dynamic_odt dual_SD[4] = {
        }
 };
-static const struct dynamic_odt dual_SS[4] = {
+__maybe_unused static const struct dynamic_odt dual_SS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_ALL,
@@ -406,7 +406,7 @@ static const struct dynamic_odt dual_SS[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_D0[4] = {
+__maybe_unused static const struct dynamic_odt dual_D0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_SAME_DIMM,
@@ -423,7 +423,7 @@ static const struct dynamic_odt dual_D0[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_0D[4] = {
+__maybe_unused static const struct dynamic_odt dual_0D[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -440,7 +440,7 @@ static const struct dynamic_odt dual_0D[4] = {
        }
 };
-static const struct dynamic_odt dual_S0[4] = {
+__maybe_unused static const struct dynamic_odt dual_S0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,
@@ -453,7 +453,7 @@ static const struct dynamic_odt dual_S0[4] = {
};
-static const struct dynamic_odt dual_0S[4] = {
+__maybe_unused static const struct dynamic_odt dual_0S[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -466,7 +466,7 @@ static const struct dynamic_odt dual_0S[4] = {
};
-static const struct dynamic_odt odt_unknown[4] = {
+__maybe_unused static const struct dynamic_odt odt_unknown[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,
@@ -493,14 +493,14 @@ static const struct dynamic_odt odt_unknown[4] = {
        }
 };
 #else  /* CONFIG_SYS_FSL_DDR3 */
-static const struct dynamic_odt single_Q[4] = {
+__maybe_unused static const struct dynamic_odt single_Q[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt single_D[4] = {
+__maybe_unused static const struct dynamic_odt single_D[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -517,7 +517,7 @@ static const struct dynamic_odt single_D[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt single_S[4] = {
+__maybe_unused static const struct dynamic_odt single_S[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -529,7 +529,7 @@ static const struct dynamic_odt single_S[4] = {
        {0, 0, 0, 0},
 };
-static const struct dynamic_odt dual_DD[4] = {
+__maybe_unused static const struct dynamic_odt dual_DD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_OTHER_DIMM,
@@ -556,7 +556,7 @@ static const struct dynamic_odt dual_DD[4] = {
        }
 };
-static const struct dynamic_odt dual_DS[4] = {
+__maybe_unused static const struct dynamic_odt dual_DS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_OTHER_DIMM,
@@ -578,7 +578,7 @@ static const struct dynamic_odt dual_DS[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_SD[4] = {
+__maybe_unused static const struct dynamic_odt dual_SD[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_OTHER_DIMM,
@@ -600,7 +600,7 @@ static const struct dynamic_odt dual_SD[4] = {
        }
 };
-static const struct dynamic_odt dual_SS[4] = {
+__maybe_unused static const struct dynamic_odt dual_SS[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_OTHER_DIMM,
                FSL_DDR_ODT_OTHER_DIMM,
@@ -617,7 +617,7 @@ static const struct dynamic_odt dual_SS[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_D0[4] = {
+__maybe_unused static const struct dynamic_odt dual_D0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_ALL,
@@ -634,7 +634,7 @@ static const struct dynamic_odt dual_D0[4] = {
        {0, 0, 0, 0}
 };
-static const struct dynamic_odt dual_0D[4] = {
+__maybe_unused static const struct dynamic_odt dual_0D[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -651,7 +651,7 @@ static const struct dynamic_odt dual_0D[4] = {
        }
 };
-static const struct dynamic_odt dual_S0[4] = {
+__maybe_unused static const struct dynamic_odt dual_S0[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,
@@ -664,7 +664,7 @@ static const struct dynamic_odt dual_S0[4] = {
};
-static const struct dynamic_odt dual_0S[4] = {
+__maybe_unused static const struct dynamic_odt dual_0S[4] = {
        {0, 0, 0, 0},
        {0, 0, 0, 0},
        {       /* cs2 */
@@ -677,7 +677,7 @@ static const struct dynamic_odt dual_0S[4] = {
};
-static const struct dynamic_odt odt_unknown[4] = {
+__maybe_unused static const struct dynamic_odt odt_unknown[4] = {
        {       /* cs0 */
                FSL_DDR_ODT_NEVER,
                FSL_DDR_ODT_CS,

    