Unverified Commit 51affef3 authored by Javier Martinez Canillas's avatar Javier Martinez Canillas
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drm/ssd130x: Silence a `dubious: x & !y` warning 



The sparse tool complains with the following warning:

$ make M=drivers/gpu/drm/solomon/ C=2
  CC [M]  drivers/gpu/drm/solomon/ssd130x.o
  CHECK   drivers/gpu/drm/solomon/ssd130x.c
drivers/gpu/drm/solomon/ssd130x.c:363:21: warning: dubious: x & !y

This seems to be a false positive in my opinion but still we can silence
the tool while making the code easier to read. Let's also add a comment,
to explain why the "com_seq" logical not is used rather than its value.

Reported-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230121190930.2804224-1-javierm@redhat.com
parent 998101f2

drivers/gpu/drm/solomon/ssd130x.c

+9 −2
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ 
#define SSD130X_SET_PRECHARGE_PERIOD2_MASK	GENMASK(7, 4)

#define SSD130X_SET_PRECHARGE_PERIOD2_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val))

#define SSD130X_SET_COM_PINS_CONFIG1_MASK	GENMASK(4, 4)

#define SSD130X_SET_COM_PINS_CONFIG1_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, !(val))

#define SSD130X_SET_COM_PINS_CONFIG1_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, (val))

#define SSD130X_SET_COM_PINS_CONFIG2_MASK	GENMASK(5, 5)

#define SSD130X_SET_COM_PINS_CONFIG2_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG2_MASK, (val))
@@ -298,6 +298,7 @@ static void ssd130x_power_off(struct ssd130x_device *ssd130x) 
static int ssd130x_init(struct ssd130x_device *ssd130x)

{

	u32 precharge, dclk, com_invdir, compins, chargepump, seg_remap;

	bool scan_mode;

	int ret;



	/* Set initial contrast */
@@ -360,7 +361,13 @@ static int ssd130x_init(struct ssd130x_device *ssd130x) 


	/* Set COM pins configuration */

	compins = BIT(1);

	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(ssd130x->com_seq) |

	/*

	 * The COM scan mode field values are the inverse of the boolean DT

	 * property "solomon,com-seq". The value 0b means scan from COM0 to

	 * COM[N - 1] while 1b means scan from COM[N - 1] to COM0.

	 */

	scan_mode = !ssd130x->com_seq;

	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(scan_mode) |

		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));

	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);

	if (ret < 0)