On Fri, 21 Apr 2017 22:28:05 +0200, Pierre-Louis Bossart wrote:
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.
Well, I somehow hesitated a complete override, but yeah, it'd be sometimes more helpful. OK, let me respin the patch quickly...
thanks,
Takashi