[PATCH v5 08/22] drm/modes: Move named modes parsing to a separate function

Maxime Ripard
2022-10-13T13:26:59Z

The current construction of the named mode parsing doesn't allow to extend
it easily. Let's move it to a separate function so we can add more
parameters and modes.

In order for the tests to still pass, some extra checks are needed, so
it's not a 1:1 move.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

---
Changes in v4:
- Fold down all the named mode patches that were split into a single
patch again to maintain bisectability
---
drivers/gpu/drm/drm_modes.c | 73 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 62 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index c0dceff51cac..2f020ef2ddf2 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -2229,6 +2229,55 @@ static const char * const drm_named_modes_whitelist[] = {
"PAL",
};

+static int drm_mode_parse_cmdline_named_mode(const char *name,
+ unsigned int name_end,
+ struct drm_cmdline_mode *cmdline_mode)
+{
+ unsigned int i;
+
+ if (!name_end)
+ return 0;
+
+ /* If the name starts with a digit, it's not a named mode */
+ if (isdigit(name[0]))
+ return 0;
+
+ /*
+ * If there's an equal sign in the name, the command-line
+ * contains only an option and no mode.
+ */
+ if (strnchr(name, name_end, '='))
+ return 0;
+
+#define STR_STRICT_EQ(str, len, cmp) \
+ (str_has_prefix(str, cmp) == len)
+
+ /* The connection status extras can be set without a mode. */
+ if (STR_STRICT_EQ(name, name_end, "d") ||
+ STR_STRICT_EQ(name, name_end, "D") ||
+ STR_STRICT_EQ(name, name_end, "e"))
+ return 0;
+
+ /*
+ * We're sure we're a named mode at that point, iterate over the
+ * list of modes we're aware of.
+ */
+ for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++) {
+ int ret;
+
+ ret = str_has_prefix(name, drm_named_modes_whitelist[i]);
+ if (ret != name_end)
+ continue;
+
+ strcpy(cmdline_mode->name, drm_named_modes_whitelist[i]);
+ cmdline_mode->specified = true;
+
+ return 1;
+ }
+
+ return -EINVAL;
+}
+
/**
* drm_mode_parse_command_line_for_connector - parse command line modeline for connector
* @mode_option: optional per connector mode option
@@ -2265,7 +2314,7 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
const char *bpp_ptr = NULL, *refresh_ptr = NULL, *extra_ptr = NULL;
const char *options_ptr = NULL;
char *bpp_end_ptr = NULL, *refresh_end_ptr = NULL;
- int i, len, ret;
+ int len, ret;

memset(mode, 0, sizeof(*mode));
mode->panel_orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
@@ -2306,17 +2355,19 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
parse_extras = true;
}

- /* First check for a named mode */
- for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++) {
- ret = str_has_prefix(name, drm_named_modes_whitelist[i]);
- if (ret == mode_end) {
- if (refresh_ptr)
- return false; /* named + refresh is invalid */

- strcpy(mode->name, drm_named_modes_whitelist[i]);
- mode->specified = true;
- break;
- }
+ if (mode_end) {
+ ret = drm_mode_parse_cmdline_named_mode(name, mode_end, mode);
+ if (ret < 0)
+ return false;
+
+ /*
+ * Having a mode that starts by a letter (and thus is named)
+ * and an at-sign (used to specify a refresh rate) is
+ * disallowed.
+ */
+ if (ret && refresh_ptr)
+ return false;
}

/* No named mode? Check for a normal mode argument, e.g. 1024x768 */

--
b4 0.11.0-dev-7da52