Clang reports a large stack frame in set_gamma() (-Wframe-larger-than=1024)
due to the large write_reg() call emitting 63 gamma bytes via varargs.

Send the command byte (0xB8) and the gamma payload using
fbtft_write_buf_dc() to avoid the varargs/NUMARGS stack blow-up.

No functional change intended.

Signed-off-by: Sun Jian <[email protected]>
---
 drivers/staging/fbtft/fb_ssd1351.c | 35 +++++++++++++-----------------
 1 file changed, 15 insertions(+), 20 deletions(-)

diff --git a/drivers/staging/fbtft/fb_ssd1351.c 
b/drivers/staging/fbtft/fb_ssd1351.c
index 6736b09b2f45..b4ab2c81e528 100644
--- a/drivers/staging/fbtft/fb_ssd1351.c
+++ b/drivers/staging/fbtft/fb_ssd1351.c
@@ -119,43 +119,38 @@ static int set_var(struct fbtft_par *par)
  */
 static int set_gamma(struct fbtft_par *par, u32 *curves)
 {
-       unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
+       u8 data[GAMMA_LEN];
+       u8 cmd = 0xB8;
        int i, acc = 0;
+       int ret;
 
-       for (i = 0; i < 63; i++) {
+       for (i = 0; i < GAMMA_LEN; i++) {
                if (i > 0 && curves[i] < 2) {
                        dev_err(par->info->device,
                                "Illegal value in Grayscale Lookup Table at 
index %d : %d. Must be greater than 1\n",
                                i, curves[i]);
                        return -EINVAL;
                }
+
                acc += curves[i];
-               tmp[i] = acc;
+
                if (acc > 180) {
                        dev_err(par->info->device,
                                "Illegal value(s) in Grayscale Lookup Table. At 
index=%d : %d, the accumulated value has exceeded 180\n",
                                i, acc);
                        return -EINVAL;
                }
+
+               data[i] = acc;
        }
 
-       write_reg(par, 0xB8,
-                 tmp[0],  tmp[1],  tmp[2],  tmp[3],
-                 tmp[4],  tmp[5],  tmp[6],  tmp[7],
-                 tmp[8],  tmp[9],  tmp[10], tmp[11],
-                 tmp[12], tmp[13], tmp[14], tmp[15],
-                 tmp[16], tmp[17], tmp[18], tmp[19],
-                 tmp[20], tmp[21], tmp[22], tmp[23],
-                 tmp[24], tmp[25], tmp[26], tmp[27],
-                 tmp[28], tmp[29], tmp[30], tmp[31],
-                 tmp[32], tmp[33], tmp[34], tmp[35],
-                 tmp[36], tmp[37], tmp[38], tmp[39],
-                 tmp[40], tmp[41], tmp[42], tmp[43],
-                 tmp[44], tmp[45], tmp[46], tmp[47],
-                 tmp[48], tmp[49], tmp[50], tmp[51],
-                 tmp[52], tmp[53], tmp[54], tmp[55],
-                 tmp[56], tmp[57], tmp[58], tmp[59],
-                 tmp[60], tmp[61], tmp[62]);
+       ret = fbtft_write_buf_dc(par, &cmd, 1, 0);
+       if (ret < 0)
+               return ret;
+
+       ret = fbtft_write_buf_dc(par, data, sizeof(data), 1);
+       if (ret < 0)
+               return ret;
 
        return 0;
 }
-- 
2.43.0

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