Re: [PATCH 3/3] mailbox: ACPI: erroneous error message when parsing the ACPI PCCT

From: kbuild test robot
Date: Wed Apr 04 2018 - 16:40:10 EST


Hi Al,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on pm/linux-next]
[also build test WARNING on v4.16 next-20180404]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Al-Stone/ACPI-improve-function-documentation-for-acpi_parse_entries_array/20180404-151910
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next

smatch warnings:
drivers/mailbox/pcc.c:392 count_pcc_subspaces() warn: always true condition '(pcct_ss->header.type >= 0) => (0-255 >= 0)'

vim +392 drivers/mailbox/pcc.c

374
375 /*+
376 *
377 * count_pcc_subspaces -- Count the PCC subspaces that are not used in
378 * reduced hardware systems.
379 * @header: Pointer to the ACPI subtable header under the PCCT.
380 * @end: End of subtable entry.
381 *
382 * Return: 0 for Success, else errno.
383 *
384 * This gets called for each entry in the PCC table.
385 */
386 static int count_pcc_subspaces(struct acpi_subtable_header *header,
387 const unsigned long end)
388 {
389 struct acpi_pcct_subspace *pcct_ss =
390 (struct acpi_pcct_subspace *) header;
391
> 392 if ((pcct_ss->header.type >= ACPI_PCCT_TYPE_GENERIC_SUBSPACE) &&
393 (pcct_ss->header.type <= ACPI_PCCT_TYPE_RESERVED) &&
394 (pcct_ss->header.type != ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) &&
395 (pcct_ss->header.type !=
396 ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
397 pr_warn("PCCT count: useful subtype = %d\n",
398 pcct_ss->header.type);
399 return 0;
400 }
401 pr_warn("PCCT count: unwanted subtype = %d\n", pcct_ss->header.type);
402 return -EINVAL;
403 }
404

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