[PATCH v2 3/3] wifi: ath12k: update EMLSR capabilities of ML Station

[Johannes Berg]

On Fri, 2025-01-17 at 22:34 +0530, Rameshkumar Sundaram wrote:
> 
> +static u32 ath12k_wmi_get_emlsr_pad_delay_us(u16 eml_cap)
> +{
> +	/* IEEE Std 802.11be-2024 Table 9-417i—Encoding of the EMLSR
> +	 * Padding Delay subfield.
> +	 */
> +	u32 pad_delay = u16_get_bits(eml_cap, IEEE80211_EML_CAP_EMLSR_PADDING_DELAY);
> +	static const u32 pad_delay_us[EMLSR_PAD_DELAY_MAX] = {0, 32, 64, 128, 256};
> +
> +	if (pad_delay >= EMLSR_PAD_DELAY_MAX)
> +		return 0;
> +
> +	return pad_delay_us[pad_delay];
> +}
> +
> +static u32 ath12k_wmi_get_emlsr_trans_delay_us(u16 eml_cap)
> +{
> +	/* IEEE Std 802.11be-2024 Table 9-417j—Encoding of the EMLSR
> +	 * Transition Delay subfield.
> +	 */
> +	u32 trans_delay = u16_get_bits(eml_cap,
> +				       IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY);
> +	static const u32 trans_delay_us[EMLSR_TRANS_DELAY_MAX] = {
> +		0, 16, 32, 64, 128, 256
> +	};
> +
> +	if (trans_delay >= EMLSR_TRANS_DELAY_MAX)
> +		return 0;
> +
> +	return trans_delay_us[trans_delay];
> +}
> +
> +static u32 ath12k_wmi_get_emlsr_trans_timeout_us(u16 eml_cap)
> +{
> +	/* IEEE Std 802.11be-2024 Table 9-417m—Encoding of the
> +	 * Transition Timeout subfield.
> +	 */
> +	u8 timeout = u16_get_bits(eml_cap, IEEE80211_EML_CAP_TRANSITION_TIMEOUT);
> +	static const u32 trans_timeout_us[EML_TRANS_TIMEOUT_MAX] = {
> +		0, 128, 256, 512,
> +		TU_TO_USEC(1),
> +		TU_TO_USEC((1U << 1)),
> +		TU_TO_USEC((1U << 2)),
> +		TU_TO_USEC((1U << 3)),
> +		TU_TO_USEC((1U << 4)),
> +		TU_TO_USEC((1U << 5)),
> +		TU_TO_USEC((1U << 6)),
> +	};
> +
> +	if (timeout >= EML_TRANS_TIMEOUT_MAX)
> +		return 0;
> +
> +	return trans_timeout_us[timeout];
> +}
> 

Some of these should probably be in ieee80211.h, and also - making a
table of shifted values? That seems ... awkward at best?

static inline u32 ieee80211_emlsr_delay_in_us(u16 eml_cap)
{
	/* IEEE Std 802.11be-2024 Table 9-417j—Encoding of the EMLSR
	 * Transition Delay subfield.
	 */
	u32 trans_delay = u16_get_bits(eml_cap,
				       IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY);


	/* invalid values also just use 0 */
	if (!trans_delay ||
	    trans_delay > IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_256US)
		return 0;

	return 16 * (1 << (trans_delay - 1));
}

seems a lot more effective?

johannes