video: fbdev: omapfb: Fix set but not used warnings in dsi

Fix several W=1 warnings.
This removes unused code and avoids an assignment by moving
the use inside the conditional block.

The register read FLD_GET(r, 15, 8) could be dropped as it was done a
few lines before too.

v2:
  - Updated subject (Lee)
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Lee Jones <lee.jones@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201128224114.1033617-23-sam@ravnborg.org

drivers/video/fbdev/omap2/omapfb/dss/dsi.c

@@ -1178,13 +1178,12 @@ static int dsi_regulator_init(struct platform_device *dsidev)
 
 static void _dsi_print_reset_status(struct platform_device *dsidev)
 {
-	u32 l;
 	int b0, b1, b2;
 
 	/* A dummy read using the SCP interface to any DSIPHY register is
 	 * required after DSIPHY reset to complete the reset of the DSI complex
 	 * I/O. */
-	l = dsi_read_reg(dsidev, DSI_DSIPHY_CFG5);
+	dsi_read_reg(dsidev, DSI_DSIPHY_CFG5);
 
 	if (dss_has_feature(FEAT_DSI_REVERSE_TXCLKESC)) {
 		b0 = 28;
@@ -3627,7 +3626,7 @@ static int dsi_proto_config(struct platform_device *dsidev)
 static void dsi_proto_timings(struct platform_device *dsidev)
 {
 	struct dsi_data *dsi = dsi_get_dsidrv_data(dsidev);
-	unsigned tlpx, tclk_zero, tclk_prepare, tclk_trail;
+	unsigned tlpx, tclk_zero, tclk_prepare;
 	unsigned tclk_pre, tclk_post;
 	unsigned ths_prepare, ths_prepare_ths_zero, ths_zero;
 	unsigned ths_trail, ths_exit;
@@ -3646,7 +3645,6 @@ static void dsi_proto_timings(struct platform_device *dsidev)
 
 	r = dsi_read_reg(dsidev, DSI_DSIPHY_CFG1);
 	tlpx = FLD_GET(r, 20, 16) * 2;
-	tclk_trail = FLD_GET(r, 15, 8);
 	tclk_zero = FLD_GET(r, 7, 0);
 
 	r = dsi_read_reg(dsidev, DSI_DSIPHY_CFG2);
@@ -4040,7 +4038,6 @@ static int dsi_update(struct omap_dss_device *dssdev, int channel,
 {
 	struct platform_device *dsidev = dsi_get_dsidev_from_dssdev(dssdev);
 	struct dsi_data *dsi = dsi_get_dsidrv_data(dsidev);
-	u16 dw, dh;
 
 	dsi_perf_mark_setup(dsidev);
 
@@ -4049,11 +4046,8 @@ static int dsi_update(struct omap_dss_device *dssdev, int channel,
 	dsi->framedone_callback = callback;
 	dsi->framedone_data = data;
 
-	dw = dsi->timings.x_res;
-	dh = dsi->timings.y_res;
-
 #ifdef DSI_PERF_MEASURE
-	dsi->update_bytes = dw * dh *
+	dsi->update_bytes = dsi->timings.x_res * dsi->timings.y_res *
 		dsi_get_pixel_size(dsi->pix_fmt) / 8;
 #endif
 	dsi_update_screen_dispc(dsidev);