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

[kbuild test robot <lkp@intel.com>]

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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