i3c master: GETMRL's 3rd byte is optional even with BCR_IBI_PAYLOAD (b4203ce0) · Commits · 戴 / test

According to the I3C spec v1.1 document, GETMRL's payload is 2 bytes, with an optional 3rd byte if the IBI private payload is larger than 1 byte. The whole GETMRL may also be optional so max_ibi_len already defaults to 1 if BCR_IBI_PAYLOAD prior to the i3c_master_getmrl_locked() call. Signed-off-by:

Nicolas Pitre <npitre@baylibre.com> Signed-off-by:

Boris Brezillon <boris.brezillon@collabora.com> Link: https://lore.kernel.org/linux-i3c/nycvar.YSQ.7.76.2004151623060.2671@knanqh.ubzr

drivers/i3c/master.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -1008,7 +1008,6 @@ static int i3c_master_getmrl_locked(struct i3c_master_controller *master,
		struct i3c_device_info *info)
		{
		struct i3c_ccc_cmd_dest dest;
		unsigned int expected_len;
		struct i3c_ccc_mrl *mrl;
		struct i3c_ccc_cmd cmd;
		int ret;
		@@ -1024,22 +1023,23 @@ static int i3c_master_getmrl_locked(struct i3c_master_controller *master,
		if (!(info->bcr & I3C_BCR_IBI_PAYLOAD))
		dest.payload.len -= 1;

		expected_len = dest.payload.len;
		i3c_ccc_cmd_init(&cmd, true, I3C_CCC_GETMRL, &dest, 1);
		ret = i3c_master_send_ccc_cmd_locked(master, &cmd);
		if (ret)
		goto out;

		if (dest.payload.len != expected_len) {
		switch (dest.payload.len) {
		case 3:
		info->max_ibi_len = mrl->ibi_len;
		fallthrough;
		case 2:
		info->max_read_len = be16_to_cpu(mrl->read_len);
		break;
		default:
		ret = -EIO;
		goto out;
		}

		info->max_read_len = be16_to_cpu(mrl->read_len);

		if (info->bcr & I3C_BCR_IBI_PAYLOAD)
		info->max_ibi_len = mrl->ibi_len;

		out:
		i3c_ccc_cmd_dest_cleanup(&dest);

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