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Commit 6174bac8 authored by Vaidyanathan Srinivasan's avatar Vaidyanathan Srinivasan Committed by Benjamin Herrenschmidt
Browse files

powerpc/cpufreq: Add pr_warn() on OPAL firmware failures 



Cpufreq depends on platform firmware to implement PStates.  In case of
platform firmware failure, cpufreq should not panic host kernel with
BUG_ON().  Less severe pr_warn() will suffice.

Add firmware_has_feature(FW_FEATURE_OPALv3) check to
skip probing for device-tree on non-powernv platforms.

Signed-off-by: default avatarVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent b00fc6ec

drivers/cpufreq/powernv-cpufreq.c

+16 −2
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/of.h>



#include <asm/cputhreads.h>

#include <asm/firmware.h>

#include <asm/reg.h>

#include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */
@@ -98,7 +99,11 @@ static int init_powernv_pstates(void) 
		return -ENODEV;

	}



	WARN_ON(len_ids != len_freqs);

	if (len_ids != len_freqs) {

		pr_warn("Entries in ibm,pstate-ids and "

			"ibm,pstate-frequencies-mhz does not match\n");

	}



	nr_pstates = min(len_ids, len_freqs) / sizeof(u32);

	if (!nr_pstates) {

		pr_warn("No PStates found\n");
@@ -131,7 +136,12 @@ static unsigned int pstate_id_to_freq(int pstate_id) 
	int i;



	i = powernv_pstate_info.max - pstate_id;

	BUG_ON(i >= powernv_pstate_info.nr_pstates || i < 0);

	if (i >= powernv_pstate_info.nr_pstates || i < 0) {

		pr_warn("PState id %d outside of PState table, "

			"reporting nominal id %d instead\n",

			pstate_id, powernv_pstate_info.nominal);

		i = powernv_pstate_info.max - powernv_pstate_info.nominal;

	}



	return powernv_freqs[i].frequency;

}
@@ -321,6 +331,10 @@ static int __init powernv_cpufreq_init(void) 
{

	int rc = 0;



	/* Don't probe on pseries (guest) platforms */

	if (!firmware_has_feature(FW_FEATURE_OPALv3))

		return -ENODEV;



	/* Discover pstates from device tree and init */

	rc = init_powernv_pstates();

	if (rc) {