Re: [PATCH v2] ALSA: hda/tas2781: Fix the order of TAS2781 calibrated-data

On Wed, 03 Sep 2025 06:13:51 +0200, Shenghao Ding wrote:

A bug reported by one of my customers that the order of TAS2781 calibrated-data is incorrect, the correct way is to move R0_Low and insert it between R0 and InvR0.

Fixes: 4fe238513407 ("ALSA: hda/tas2781: Move and unified the calibrated-data getting function for SPI and I2C into the tas2781_hda lib") Signed-off-by: Shenghao Ding shenghao-ding@ti.com

---

v2:

• Submit to sound branch maintianed by Tiwai instead of linux-next branch
• drop other fix

---

sound/hda/codecs/side-codecs/tas2781_hda.c | 38 ++++++++++++++++++---- 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/sound/hda/codecs/side-codecs/tas2781_hda.c b/sound/hda/codecs/side-codecs/tas2781_hda.c index f46d2e06c64f..cd9990869e18 100644 --- a/sound/hda/codecs/side-codecs/tas2781_hda.c +++ b/sound/hda/codecs/side-codecs/tas2781_hda.c @@ -33,6 +33,32 @@ const efi_guid_t tasdev_fct_efi_guid[] = { }; EXPORT_SYMBOL_NS_GPL(tasdev_fct_efi_guid, "SND_HDA_SCODEC_TAS2781");

+/*

• • The order of calibrated-data writing is a bit different from the order
• • in UEFI. Here is the conversion to match the order of calibrated-data
• • writing.
• */

+static void cali_cnv(unsigned char *data, unsigned int base, int offset) +{

• __be32 bedata[TASDEV_CALIB_N];
• int i;
• /* r0_reg */
• bedata[0] = cpu_to_be32(*(uint32_t *)&data[base]);
• /* r0_low_reg */
• bedata[1] = cpu_to_be32(*(uint32_t *)&data[base + 8]);
• /* invr0_reg */
• bedata[2] = cpu_to_be32(*(uint32_t *)&data[base + 4]);
• /* pow_reg */
• bedata[3] = cpu_to_be32(*(uint32_t *)&data[base + 12]);
• /* tlimit_reg */
• bedata[4] = cpu_to_be32(*(uint32_t *)&data[base + 16]);
• for (i = 0; i < TASDEV_CALIB_N; i++)

• memcpy(&data[offset + i * 4 + 1], &bedata[i],
  

• 	sizeof(bedata[i]));
  

+}

IMO, this can be more readable when you use struct calidata, e.g.

static void cali_cnv(unsigned char *data, unsigned int base, int offset) { struct calidata reg;

reg.r0_reg = *(u32 *)&data[base] reg.r0_low_reg = *(u32 *)&data[base + 8] reg.invr0_reg = *(u32 *)&data[base + 4] reg.pow_reg = *(u32 *)&data[base + 12]; reg.tlimit_reg = *(u32 *)&data[base + 16]);

cpu_to_be32_array((__force __be32 *)(data + offset + 1), &reg, TASDEV_CALIB_N); }

... or even simpler like:

static void cali_cnv(unsigned char *data, unsigned int base, int offset) { struct calidata reg;

memcpy(&reg, data, sizeof(reg)); /* the data order has to be swapped between r0_low_reg and inv0_reg */ swap(reg.r0_low_reg, reg.invr0_reg);

cpu_to_be32_array((__force __be32 *)(data + offset + 1), &reg, TASDEV_CALIB_N); }

static void tas2781_apply_calib(struct tasdevice_priv *p) { struct calidata *cali_data = &p->cali_data; @@ -86,6 +112,7 @@ static void tas2781_apply_calib(struct tasdevice_priv *p)

for (j = 0, k = 0; j < node_num; j++) {
	oft = j * 6 + 3;

• 	/* Calibration registers address */
  

Don't try to add unrelated changes. This comment won't fix or explain what your patch does. If any, make another patch to update / add more comments. Putting unrelated changes disturbs the patch readability *a lot*

	if (tmp_val[oft] == TASDEV_UEFI_CALI_REG_ADDR_FLG) {
		for (i = 0; i < TASDEV_CALIB_N; i++) {
			buf = &data[(oft + i + 1) * 4];

@@ -93,6 +120,7 @@ static void tas2781_apply_calib(struct tasdevice_priv *p) buf[2], buf[3]); } } else {

• 		/* Calibrated data */
  

Ditto.

@@ -127,12 +154,11 @@ static void tas2781_apply_calib(struct tasdevice_priv *p) dev_err(p->dev, "%s: V1 CRC error\n", __func__); return; }

• /* reverse rearrangement in case of overlap */
  

Ditto.

thanks,

Takashi