Hi all, I am using a dev board with a Cirrus Logic cs24l51 codec. This used to work fine prior to kernel version 5.x, however after 5.x it is not possible to set certain values for ALSA controls from userspace. I believe this is related to the input validation that is mentioned in this thread: https://lore.kernel.org/all/Yph8C3bRxcr6ogW7@xxxxxxxxxxxxx/T/, and possibly in this commit: 4f1e50d6a9cf9c1b8c859d449b5031cacfa8404e ("ASoC: ops: Reject out of bounds values in snd_soc_put_volsw_sx()") For the cs24l51, all the controls that fail are using the SOC_DOUBLE_R_SX_TLV macro. I have traced this to the checks in snd_soc_put_volsw_sx, specifically the (val > max - min) check: pr_warn("Max: %d, Min: %d, Value: %d", max, min, val); pr_warn("platform_max: %d", mc->platform_max); if (mc->platform_max && val > mc->platform_max) { return -EINVAL; } if (val > max - min){ pr_warn("(val > max - min) check failed"); return -EINVAL; } if (val < 0) return -EINVAL; According to the datasheet of the CS24L51, section 6.13, page 61, the PCMMIXX_VOL registers accept the following range of values: Binary Code / Volume Setting 001 1000 / +12.0 dB ··· ··· 000 0000 / 0 dB 111 1111 / -0.5 dB 111 1110 / -1.0 dB ··· ··· 001 1001 / -51.5 dB Minimum value is 0x19 (001 1001) corresponding to -51.5 dB, then there are 127 possible gain settings from -51.5 dB to +12.0 dB, in 0.5 dB steps. This is declared in the driver as follows: SOC_DOUBLE_R_SX_TLV("PCM Playback Volume", CS42L51_PCMA_VOL, CS42L51_PCMB_VOL, 0, 0x19, 0x7F, adc_pcm_tlv), 0x19 = min value 0x7F = number of gain settings This seems to be correct according to the semantics of the SOC_DOUBLE_R_SX_TLV macro as described in commit 34198710f55b5f359f43e67d9a08fe5aadfbca1b ("ASoC: Add info callback for SX_TLV controls"). However, the (val > max - min) check in snd_soc_put_volsw_sx fails in the above example because val = 127, max - min = 127 - 25 = 102. So I am not sure how this should be fixed. Is the SX_TLV macro being used incorrectly here? Is the check in snd_soc_put_volsw_sx wrong? Any pointers are welcome. Thanks, (If possible, please CC me in any replies) Guillermo Rodriguez Garcia guille.rodriguez@xxxxxxxxx
