On 04/21/2017 03:15 PM, Takashi Iwai wrote:
The bytcr-rt5640 driver has a few quirk setups depending on the board,
where the quirk value is set by DMI matching. When you have a new
device to add the support, you often experience to try the different
quirk by trial-and-error. Or, you may have a development model that
still has no proper DMI string. In either case, you'd need to compile
the driver at each time.
This patch introduces a module option to override the quirk value on
the fly. User can boot like snd-soc-sst-bytcr-rt5640.quirk=0x4004 to
override the default value without recompilation. It's a raw value,
so user needs to check the source code for the meaning of each bit.
I am doing similar things at the moment, I folded IN1 and IN3 quirks
together and was about to add a control to force
single-ended/differential mics. The use of a parameter is not bad, we
could stick it in a modprobe file and avoid writing more code.
That said, unless I am missing something, the problem with this
parameter is that it will be overwritten by
DMI quirks or the settings detected by the driver, see e.g. this code.
/* change defaults for Baytrail-CR capture */
byt_rt5640_quirk |= BYT_RT5640_IN1_MAP;
byt_rt5640_quirk |= BYT_RT5640_DIFF_MIC;
} else {
byt_rt5640_quirk |= (BYT_RT5640_DMIC1_MAP |
BYT_RT5640_DMIC_EN);
}
/* check quirks before creating card */
dmi_check_system(byt_rt5640_quirk_table);
log_quirks(&pdev->dev);
We may need a second variable to force the .quirk parameter to be used
as is and avoid applying changes done at run-time.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/soc/intel/boards/bytcr_rt5640.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/soc/intel/boards/bytcr_rt5640.c b/sound/soc/intel/boards/bytcr_rt5640.c
index 5c7219fb3aa8..b848cbf575a1 100644
--- a/sound/soc/intel/boards/bytcr_rt5640.c
+++ b/sound/soc/intel/boards/bytcr_rt5640.c
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/device.h>
@@ -57,7 +58,9 @@ struct byt_rt5640_private {
struct clk *mclk;
};
-static unsigned long byt_rt5640_quirk = BYT_RT5640_MCLK_EN;
+static unsigned int byt_rt5640_quirk = BYT_RT5640_MCLK_EN;
+module_param_named(quirk, byt_rt5640_quirk, int, 0444);
+MODULE_PARM_DESC(quirk, "Board-specific quirk override");
static void log_quirks(struct device *dev)
{
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