diff mbox series

[v5,11/11] drm/mediatek: gamma: Program gamma LUT type for descending or rising

Message ID 20230601121022.2401844-12-angelogioacchino.delregno@collabora.com (mailing list archive)
State New, archived
Headers show
Series MediaTek DDP GAMMA - 12-bit LUT support | expand

Commit Message

AngeloGioacchino Del Regno June 1, 2023, 12:10 p.m. UTC 
All of the SoCs that don't have dithering control in the gamma IP
have got a GAMMA_LUT_TYPE bit that tells to the IP if the LUT is
"descending" (bit set) or "rising" (bit cleared): make sure to set
it correctly after programming the LUT.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_gamma.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

Comments

Dan Carpenter June 10, 2023, 6:58 a.m. UTC | #1 
Hi AngeloGioacchino,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/AngeloGioacchino-Del-Regno/drm-mediatek-gamma-Adjust-mtk_drm_gamma_set_common-parameters/20230601-222357
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230601121022.2401844-12-angelogioacchino.delregno%40collabora.com
patch subject: [PATCH v5 11/11] drm/mediatek: gamma: Program gamma LUT type for descending or rising
config: arm64-randconfig-m031-20230608 (https://download.01.org/0day-ci/archive/20230610/202306101458.lRXHEE0Z-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 12.3.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202306101458.lRXHEE0Z-lkp@intel.com/

smatch warnings:
drivers/gpu/drm/mediatek/mtk_disp_gamma.c:192 mtk_gamma_set_common() error: we previously assumed 'gamma->data' could be null (see line 120)

vim +192 drivers/gpu/drm/mediatek/mtk_disp_gamma.c

4873468a82b553 Jason-JH.Lin               2023-06-01  103  void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
69a4237ab1d13a Yongqiang Niu              2021-01-29  104  {
4873468a82b553 Jason-JH.Lin               2023-06-01  105  	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  106  	void __iomem *lut0_base = regs + DISP_GAMMA_LUT;
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  107  	void __iomem *lut1_base = regs + DISP_GAMMA_LUT1;
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  108  	u32 cfg_val, data_mode, lbank_val, word[2];
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  109  	int cur_bank, num_lut_banks;
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  110  	u16 lut_bank_size, lut_size;
69a4237ab1d13a Yongqiang Niu              2021-01-29  111  	struct drm_color_lut *lut;
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  112  	unsigned int i;
4873468a82b553 Jason-JH.Lin               2023-06-01  113  	bool lut_diff;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  114  	u8 lut_bits;
69a4237ab1d13a Yongqiang Niu              2021-01-29  115  
e824bd353592b5 AngeloGioacchino Del Regno 2023-06-01  116  	/* If there's no gamma lut there's nothing to do here. */
e824bd353592b5 AngeloGioacchino Del Regno 2023-06-01  117  	if (!state->gamma_lut)
e824bd353592b5 AngeloGioacchino Del Regno 2023-06-01  118  		return;
e824bd353592b5 AngeloGioacchino Del Regno 2023-06-01  119  
ca340e013e3733 AngeloGioacchino Del Regno 2023-06-01 @120  	if (gamma && gamma->data) {
                                                                             ^^^^^^^^^^^
This code assumes "gamma->data" can be NULL

4873468a82b553 Jason-JH.Lin               2023-06-01  121  		lut_diff = gamma->data->lut_diff;
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  122  		lut_bank_size = gamma->data->lut_bank_size;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  123  		lut_bits = gamma->data->lut_bits;
ca340e013e3733 AngeloGioacchino Del Regno 2023-06-01  124  		lut_size = gamma->data->lut_size;
ca340e013e3733 AngeloGioacchino Del Regno 2023-06-01  125  	} else {
4873468a82b553 Jason-JH.Lin               2023-06-01  126  		lut_diff = false;
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  127  		lut_bank_size = LUT_SIZE_DEFAULT;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  128  		lut_bits = LUT_BITS_DEFAULT;
ca340e013e3733 AngeloGioacchino Del Regno 2023-06-01  129  		lut_size = LUT_SIZE_DEFAULT;
ca340e013e3733 AngeloGioacchino Del Regno 2023-06-01  130  	}
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  131  	num_lut_banks = lut_size / lut_bank_size;
4873468a82b553 Jason-JH.Lin               2023-06-01  132  
ee2cb37b9ac9e2 AngeloGioacchino Del Regno 2023-06-01  133  	cfg_val = readl(regs + DISP_GAMMA_CFG);
69a4237ab1d13a Yongqiang Niu              2021-01-29  134  	lut = (struct drm_color_lut *)state->gamma_lut->data;
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  135  
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  136  	/* Switch to 12 bits data mode if supported */
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  137  	data_mode = FIELD_PREP(DISP_GAMMA_BANK_DATA_MODE, !!(lut_bits == 12));
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  138  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  139  	for (cur_bank = 0; cur_bank < num_lut_banks; cur_bank++) {
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  140  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  141  		/* Switch gamma bank and set data mode before writing LUT */
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  142  		if (num_lut_banks > 1) {
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  143  			lbank_val = FIELD_PREP(DISP_GAMMA_BANK_BANK, cur_bank);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  144  			lbank_val |= data_mode;
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  145  			writel(lbank_val, regs + DISP_GAMMA_BANK);
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  146  		}
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  147  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  148  		for (i = 0; i < lut_bank_size; i++) {
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  149  			int n = (cur_bank * lut_bank_size) + i;
77eb9fd1f1ff7c AngeloGioacchino Del Regno 2023-06-01  150  			struct drm_color_lut diff, hwlut;
77eb9fd1f1ff7c AngeloGioacchino Del Regno 2023-06-01  151  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  152  			hwlut.red = drm_color_lut_extract(lut[n].red, lut_bits);
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  153  			hwlut.green = drm_color_lut_extract(lut[n].green, lut_bits);
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  154  			hwlut.blue = drm_color_lut_extract(lut[n].blue, lut_bits);
77eb9fd1f1ff7c AngeloGioacchino Del Regno 2023-06-01  155  
ba99d08da6adec Yongqiang Niu              2022-04-28  156  			if (!lut_diff || (i % 2 == 0)) {
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  157  				if (lut_bits == 12) {
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  158  					word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, hwlut.red);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  159  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, hwlut.green);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  160  					word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, hwlut.blue);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  161  				} else {
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  162  					word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, hwlut.red);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  163  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, hwlut.green);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  164  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, hwlut.blue);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  165  				}
ba99d08da6adec Yongqiang Niu              2022-04-28  166  			} else {
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  167  				diff.red = lut[n].red - lut[n - 1].red;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  168  				diff.red = drm_color_lut_extract(diff.red, lut_bits);
77eb9fd1f1ff7c AngeloGioacchino Del Regno 2023-06-01  169  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  170  				diff.green = lut[n].green - lut[n - 1].green;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  171  				diff.green = drm_color_lut_extract(diff.green, lut_bits);
77eb9fd1f1ff7c AngeloGioacchino Del Regno 2023-06-01  172  
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  173  				diff.blue = lut[n].blue - lut[n - 1].blue;
1829ae02cf6bb6 AngeloGioacchino Del Regno 2023-06-01  174  				diff.blue = drm_color_lut_extract(diff.blue, lut_bits);
ba99d08da6adec Yongqiang Niu              2022-04-28  175  
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  176  				if (lut_bits == 12) {
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  177  					word[0] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_R, diff.red);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  178  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_12BIT_G, diff.green);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  179  					word[1] = FIELD_PREP(DISP_GAMMA_LUT_12BIT_B, diff.blue);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  180  				} else {
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  181  					word[0] = FIELD_PREP(DISP_GAMMA_LUT_10BIT_R, diff.red);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  182  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_G, diff.green);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  183  					word[0] |= FIELD_PREP(DISP_GAMMA_LUT_10BIT_B, diff.blue);
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  184  				}
ba99d08da6adec Yongqiang Niu              2022-04-28  185  			}
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  186  			writel(word[0], (lut0_base + i * 4));
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  187  			if (lut_bits == 12)
b13cb453a8db5d AngeloGioacchino Del Regno 2023-06-01  188  				writel(word[1], (lut1_base + i * 4));
69a4237ab1d13a Yongqiang Niu              2021-01-29  189  		}
a26000d47a579c AngeloGioacchino Del Regno 2023-06-01  190  	}
ee2cb37b9ac9e2 AngeloGioacchino Del Regno 2023-06-01  191  
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01 @192  	if (gamma && !gamma->data->has_dither) {
                                                                              ^^^^^^^^^^^^^
"gamma->data" is derefrenced without being checked.

3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  193  		/* Descending or Rising LUT */
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  194  		if (mtk_gamma_lut_is_descending(lut, lut_size))
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  195  			cfg_val |= FIELD_PREP(GAMMA_LUT_TYPE, 1);
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  196  		else
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  197  			cfg_val &= ~GAMMA_LUT_TYPE;
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  198  	}
3d61ac6c44ce4d AngeloGioacchino Del Regno 2023-06-01  199  
ee2cb37b9ac9e2 AngeloGioacchino Del Regno 2023-06-01  200  	/* Enable the gamma table */
2979ceb320a4ed AngeloGioacchino Del Regno 2023-06-01  201  	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);
ee2cb37b9ac9e2 AngeloGioacchino Del Regno 2023-06-01  202  
e21d98027e50c8 AngeloGioacchino Del Regno 2023-06-01  203  	/* Disable RELAY mode to pass the processed image */
e21d98027e50c8 AngeloGioacchino Del Regno 2023-06-01  204  	cfg_val &= ~GAMMA_RELAY_MODE;
e21d98027e50c8 AngeloGioacchino Del Regno 2023-06-01  205  
ee2cb37b9ac9e2 AngeloGioacchino Del Regno 2023-06-01  206  	writel(cfg_val, regs + DISP_GAMMA_CFG);
69a4237ab1d13a Yongqiang Niu              2021-01-29  207  }
diff mbox series

Patch

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
index e9655b661364..bd530e603264 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_gamma.c
@@ -23,6 +23,7 @@ 
 #define GAMMA_RELAY_MODE				BIT(0)
 #define GAMMA_LUT_EN					BIT(1)
 #define GAMMA_DITHERING					BIT(2)
+#define GAMMA_LUT_TYPE					BIT(2)
 #define DISP_GAMMA_SIZE				0x0030
 #define DISP_GAMMA_SIZE_HSIZE				GENMASK(28, 16)
 #define DISP_GAMMA_SIZE_VSIZE				GENMASK(12, 0)
@@ -89,6 +90,16 @@  unsigned int mtk_gamma_get_lut_size(struct device *dev)
 	return lut_size;
 }
 
+static bool mtk_gamma_lut_is_descending(struct drm_color_lut *lut, u32 lut_size)
+{
+	u64 first, last;
+
+	first = lut[0].red + lut[0].green + lut[0].blue;
+	last = lut[lut_size].red + lut[lut_size].green + lut[lut_size].blue;
+
+	return !!(first > last);
+}
+
 void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crtc_state *state)
 {
 	struct mtk_disp_gamma *gamma = dev_get_drvdata(dev);
@@ -178,6 +189,14 @@  void mtk_gamma_set_common(struct device *dev, void __iomem *regs, struct drm_crt
 		}
 	}
 
+	if (gamma && !gamma->data->has_dither) {
+		/* Descending or Rising LUT */
+		if (mtk_gamma_lut_is_descending(lut, lut_size))
+			cfg_val |= FIELD_PREP(GAMMA_LUT_TYPE, 1);
+		else
+			cfg_val &= ~GAMMA_LUT_TYPE;
+	}
+
 	/* Enable the gamma table */
 	cfg_val |= FIELD_PREP(GAMMA_LUT_EN, 1);