From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout05.his.huawei.com (canpmsgout05.his.huawei.com [113.46.200.220]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A7567217F33; Thu, 16 Jul 2026 11:52:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.220 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784202723; cv=none; b=XzQRR3WPSAmeLga0EBy678wX/BUos2JezrecZ9NWvmaMKlAuQTQVwSPgImyTlHWdJULA5H7ebsNMBMC763LPuDMs1Ky3YN7w07gXr7Qj4T9m/Co3smF0CF5HIXl6kIOS8B4hW2D0lt1y0bPPwahRkpwyS323ID0vzqBvWWvSmtI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784202723; c=relaxed/simple; bh=fyyERGBP2DdPmimRQUJqhmjpHfPl6vg1jEguRI83MCU=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=GJKozsGjTn+tzeLXoqqFpacq9LHA77A3/lKhWxbNWKjEzrxfhv/BC27O3fewa+nL1TnBr9is4/amYTheXNZTpUNtkmF0J1qjP4eQqVBJkulHqC6tHpjVDNtHOL9Xt28Fa9oe//iu//RQC4pvqhhpafIKis/HgycKkgfn0EFW2ho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=h-partners.com; dkim=pass (1024-bit key) header.d=h-partners.com header.i=@h-partners.com header.b=QEDFSm6e; arc=none smtp.client-ip=113.46.200.220 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=h-partners.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=h-partners.com header.i=@h-partners.com header.b="QEDFSm6e" dkim-signature: v=1; a=rsa-sha256; d=h-partners.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=UGtbuBYUDIEQNwZOAcL+fiP6CfSsr0Bd6OsMF5uyJvs=; b=QEDFSm6eVePH2YWgewuN91+xxov1gQDPdc4x7YlCZnTltDBzqoUB31Ns4a7vMAhFl4NaRhWC0 ZRF7lFJ2SLF/+zjXnDDY5B3GLT/2BVGsIUwYS+HYtFpmzU3undA+wCuAO4EhIGrreII2rqq+gDx aylS1DFB/vdIP+RaOcHJEPc= Received: from mail.maildlp.com (unknown [172.19.163.0]) by canpmsgout05.his.huawei.com (SkyGuard) with ESMTPS id 4h1B3b47L6z12LCc; Thu, 16 Jul 2026 19:42:19 +0800 (CST) Received: from kwepemo100005.china.huawei.com (unknown [7.202.195.212]) by mail.maildlp.com (Postfix) with ESMTPS id B87D840561; Thu, 16 Jul 2026 19:51:56 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemo100005.china.huawei.com (7.202.195.212) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 16 Jul 2026 19:51:56 +0800 Message-ID: Date: Thu, 16 Jul 2026 19:51:55 +0800 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 04/17] ACPI: processor: idle: Rearrange acpi_processor_evaluate_lpi() To: "Rafael J. Wysocki" , Linux PM CC: Linux ACPI , Sudeep Holla References: <4746278.LvFx2qVVIh@rafael.j.wysocki> <3426078.44csPzL39Z@rafael.j.wysocki> From: "lihuisong (C)" In-Reply-To: <3426078.44csPzL39Z@rafael.j.wysocki> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemo100005.china.huawei.com (7.202.195.212) On 7/9/2026 8:33 PM, Rafael J. Wysocki wrote: > From: "Rafael J. Wysocki" > > Rearrange acpi_processor_evaluate_lpi() to make it somewhat easier to > follow and diagnose (if need be). In particular: > > * Rename some local variables and reorder their definitions. > > * Change the type of local variables used for storing firmware-provided > values to unsigned int (they cannot be negative). > > * Eliminate local variable "loop" that is redundant. > > * Avoid explicit pointer arithmetic. > > * Print the correct number of _LPI state packages in the final debug > message. > > No intentional functional impact beyond debug output. > > Signed-off-by: Rafael J. Wysocki > --- > drivers/acpi/processor_idle.c | 64 +++++++++++++++++++---------------- > 1 file changed, 34 insertions(+), 30 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index e8682f779249..cd506e9e5a84 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -872,12 +872,12 @@ static int obj_get_integer(union acpi_object *obj, u32 *value) > static int acpi_processor_evaluate_lpi(acpi_handle handle, > struct acpi_lpi_states_array *info) > { > - acpi_status status; > - int ret = 0; > - int pkg_count, state_idx = 1, loop; > struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > - union acpi_object *lpi_data; > + union acpi_object *lpi_data, *lpi_pkg; > + unsigned int lpi_pkg_count, state_idx; > struct acpi_lpi_state *lpi_state; > + acpi_status status; > + int ret = 0; > > status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); > if (ACPI_FAILURE(status)) { > @@ -895,41 +895,46 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle, > goto end; > } > > - pkg_count = lpi_data->package.elements[2].integer.value; > + lpi_pkg_count = lpi_data->package.elements[2].integer.value; > > /* Validate number of power states. */ > - if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { > + if (!lpi_pkg_count || lpi_pkg_count != lpi_data->package.count - 3) { > acpi_handle_debug(handle, "Invalid _LPI state count\n"); > ret = -ENODATA; > goto end; > } > > - lpi_state = kzalloc_objs(*lpi_state, pkg_count); > + lpi_state = kzalloc_objs(*lpi_state, lpi_pkg_count); > if (!lpi_state) { > ret = -ENOMEM; > goto end; > } > > - info->size = pkg_count; > + info->size = lpi_pkg_count; > info->entries = lpi_state; > > - /* LPI States start at index 3 */ > - for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { > - union acpi_object *element, *pkg_elem, *obj; > + /* _LPI State packages start at index 3. */ > + lpi_pkg = &lpi_data->package.elements[3]; > > - element = &lpi_data->package.elements[loop]; > - if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) > + for (state_idx = 1; state_idx <= lpi_pkg_count; > + state_idx++, lpi_state++, lpi_pkg++) { > + union acpi_object *lpi_pkg_elem, *obj; > + > + lpi_state->index = state_idx; > + > + if (lpi_pkg->type != ACPI_TYPE_PACKAGE || lpi_pkg->package.count < 7) > continue; > > - pkg_elem = element->package.elements; > + lpi_pkg_elem = lpi_pkg->package.elements; > > - obj = pkg_elem + 6; > + /* Get the entry method first and skip the state if that fails. */ > + obj = &lpi_pkg_elem[6]; > if (obj->type == ACPI_TYPE_BUFFER) { > struct acpi_power_register *reg; > > if (obj->buffer.length < sizeof(*reg)) { > acpi_handle_debug(handle, > - "Invalid register data for _LPI state %d\n", > + "Invalid register data for _LPI state %u\n", > state_idx); > continue; > } > @@ -937,7 +942,7 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle, > reg = (struct acpi_power_register *)obj->buffer.pointer; > if (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) { > acpi_handle_debug(handle, > - "Unsupported entry method for _LPI state %d\n", > + "Unsupported entry method for _LPI state %u\n", > state_idx); > continue; > } > @@ -949,36 +954,35 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle, > lpi_state->address = obj->integer.value; > } else { > acpi_handle_debug(handle, > - "Invalid entry method for _LPI state %d\n", > + "Invalid entry method for _LPI state %u\n", > state_idx); > continue; > } > > - lpi_state->index = state_idx; > - if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { > + if (obj_get_integer(&lpi_pkg_elem[0], &lpi_state->min_residency)) { > acpi_handle_debug(handle, > - "Assuming 10 us min. residency for _LPI state %d\n", > + "Assuming 10 us min. residency for _LPI state %u\n", > state_idx); > lpi_state->min_residency = 10; > } > > - if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { > + if (obj_get_integer(&lpi_pkg_elem[1], &lpi_state->wake_latency)) { > acpi_handle_debug(handle, > - "Assuming 10 us wake latency for _LPI state %d\n", > + "Assuming 10 us wake latency for _LPI state %u\n", > state_idx); > lpi_state->wake_latency = 10; > } > > - if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) > + if (obj_get_integer(&lpi_pkg_elem[2], &lpi_state->flags)) > lpi_state->flags = 0; > > - if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) > + if (obj_get_integer(&lpi_pkg_elem[3], &lpi_state->arch_flags)) > lpi_state->arch_flags = 0; > > - if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) > + if (obj_get_integer(&lpi_pkg_elem[4], &lpi_state->res_cnt_freq)) > lpi_state->res_cnt_freq = 1; > > - if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) > + if (obj_get_integer(&lpi_pkg_elem[5], &lpi_state->enable_parent_state)) > lpi_state->enable_parent_state = 0; How about move parsing lpi_pkg_elem[6] code to here? > > /* Skip elements [7-8] i.e. Residency/Usage counters. */ > @@ -987,16 +991,16 @@ static int acpi_processor_evaluate_lpi(acpi_handle handle, > * Avoid out-of-bounds access if the size of the package is less > * than expected. > */ > - if (element->package.count < 10) > + if (lpi_pkg->package.count < 10) > continue; > > - obj = pkg_elem + 9; > + obj = &lpi_pkg_elem[9]; > if (obj->type == ACPI_TYPE_STRING) > strscpy(lpi_state->desc, obj->string.pointer, > ACPI_CX_DESC_LEN); > } > > - acpi_handle_debug(handle, "Found %d power states\n", state_idx); > + acpi_handle_debug(handle, "Found %u power states\n", lpi_pkg_count); > end: > kfree(buffer.pointer); > return ret;