Attachment 1441175 Details for Bug 1435837 – Upstream patch (as accepted in linux-pm)

[patch] Upstream patch (as accepted in linux-pm)

0001-bz1435837-error-parsing-PCC-subspaces-from-PCCT.patch (text/plain), 10.13 KB, created by Al Stone on 2018-05-24 17:41:52 UTC

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Creator: Al Stone

Created: 2018-05-24 17:41:52 UTC

Size: 10.13 KB

patch

obsolete

>From 4d0d83834dab5334fe14a551696fda48a8992780 Mon Sep 17 00:00:00 2001
>From: Al Stone <ahs3@redhat.com>
>Date: Thu, 24 May 2018 11:19:31 -0600
>Subject: [PATCH] bz1435837: error parsing PCC subspaces from PCCT
>
>Added a patch from upstream to fix this error, which as it turns out
>is an erroneous message -- i.e., there is actually no error.  Please
>see the patch file itself for further details.
>
>Signed-off-by: Al Stone <ahs3@redhat.com>
>---
> ...-erroneous-error-message-when-parsing-ACP.patch | 241 +++++++++++++++++++++
> kernel.spec                                        |   4 +
> 2 files changed, 245 insertions(+)
> create mode 100644 0001-mailbox-PCC-erroneous-error-message-when-parsing-ACP.patch
>
>diff --git a/0001-mailbox-PCC-erroneous-error-message-when-parsing-ACP.patch b/0001-mailbox-PCC-erroneous-error-message-when-parsing-ACP.patch
>new file mode 100644
>index 00000000..110ad0f5
>--- /dev/null
>+++ b/0001-mailbox-PCC-erroneous-error-message-when-parsing-ACP.patch
>@@ -0,0 +1,241 @@
>+From 8f8027c5f935bf02bdc8806c109ddbb0e402283c Mon Sep 17 00:00:00 2001
>+From: Al Stone <ahs3@redhat.com>
>+Date: Wed, 16 May 2018 16:01:41 -0600
>+Subject: [PATCH] mailbox: PCC: erroneous error message when parsing ACPI PCCT
>+
>+There have been multiple reports of the following error message:
>+
>+[    0.068293] Error parsing PCC subspaces from PCCT
>+
>+This error message is not correct.  In multiple cases examined, the PCCT
>+(Platform Communications Channel Table) concerned is actually properly
>+constructed; the problem is that acpi_pcc_probe() which reads the PCCT
>+is making the assumption that the only valid PCCT is one that contains
>+subtables of one of two types: ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE or
>+ACPI_PCCT_TYPE_HW_REDUCED_TYPE2.  The number of subtables of these
>+types are counted and as long as there is at least one of the desired
>+types, the acpi_pcc_probe() succeeds.  When no subtables of these types
>+are found, regardless of whether or not any other subtable types are
>+present, the error mentioned above is reported.
>+
>+In the cases reported to me personally, the PCCT contains exactly one
>+subtable of type ACPI_PCCT_TYPE_GENERIC_SUBSPACE.  The function
>+acpi_pcc_probe() does not count it as a valid subtable, so believes
>+there to be no valid subtables, and hence outputs the error message.
>+
>+An example of the PCCT being reported as erroneous yet perfectly fine
>+is the following:
>+
>+                    Signature : "PCCT"
>+                 Table Length : 0000006E
>+                     Revision : 05
>+                     Checksum : A9
>+                       Oem ID : "XXXXXX"
>+                 Oem Table ID : "XXXXX   "
>+                 Oem Revision : 00002280
>+              Asl Compiler ID : "XXXX"
>+        Asl Compiler Revision : 00000002
>+
>+        Flags (decoded below) : 00000001
>+                     Platform : 1
>+                     Reserved : 0000000000000000
>+
>+                Subtable Type : 00 [Generic Communications Subspace]
>+                       Length : 3E
>+
>+                     Reserved : 000000000000
>+                 Base Address : 00000000DCE43018
>+               Address Length : 0000000000001000
>+
>+            Doorbell Register : [Generic Address Structure]
>+                     Space ID : 01 [SystemIO]
>+                    Bit Width : 08
>+                   Bit Offset : 00
>+         Encoded Access Width : 01 [Byte Access:8]
>+                      Address : 0000000000001842
>+
>+                Preserve Mask : 00000000000000FD
>+                   Write Mask : 0000000000000002
>+              Command Latency : 00001388
>+          Maximum Access Rate : 00000000
>+      Minimum Turnaround Time : 0000
>+
>+To fix this, we count up all of the possible subtable types for the
>+PCCT, and only report an error when there are none (which could mean
>+either no subtables, or no valid subtables), or there are too many.
>+We also change the logic so that if there is a valid subtable, we
>+do try to initialize it per the PCCT subtable contents.  This is a
>+change in functionality; previously, the probe would have returned
>+right after the error message and would not have tried to use any
>+other subtable definition.
>+
>+Tested on my personal laptop which showed the error previously; the
>+error message no longer appears and the laptop appears to operate
>+normally.
>+
>+Signed-off-by: Al Stone <ahs3@redhat.com>
>+Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
>+Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>+---
>+ drivers/mailbox/pcc.c | 81 ++++++++++++++++++++++++---------------------------
>+ 1 file changed, 38 insertions(+), 43 deletions(-)
>+
>+diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
>+index 3ef7f036ceea..fc3c237daef2 100644
>+--- a/drivers/mailbox/pcc.c
>++++ b/drivers/mailbox/pcc.c
>+@@ -373,33 +373,24 @@ static const struct mbox_chan_ops pcc_chan_ops = {
>+ };
>+ 
>+ /**
>+- * parse_pcc_subspace - Parse the PCC table and verify PCC subspace
>+- *		entries. There should be one entry per PCC client.
>++ * parse_pcc_subspaces -- Count PCC subspaces defined
>+  * @header: Pointer to the ACPI subtable header under the PCCT.
>+  * @end: End of subtable entry.
>+  *
>+- * Return: 0 for Success, else errno.
>++ * Return: If we find a PCC subspace entry of a valid type, return 0.
>++ *	Otherwise, return -EINVAL.
>+  *
>+  * This gets called for each entry in the PCC table.
>+  */
>+ static int parse_pcc_subspace(struct acpi_subtable_header *header,
>+ 		const unsigned long end)
>+ {
>+-	struct acpi_pcct_hw_reduced *pcct_ss;
>+-
>+-	if (pcc_mbox_ctrl.num_chans <= MAX_PCC_SUBSPACES) {
>+-		pcct_ss = (struct acpi_pcct_hw_reduced *) header;
>++	struct acpi_pcct_subspace *ss = (struct acpi_pcct_subspace *) header;
>+ 
>+-		if ((pcct_ss->header.type !=
>+-				ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE)
>+-		    && (pcct_ss->header.type !=
>+-				ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
>+-			pr_err("Incorrect PCC Subspace type detected\n");
>+-			return -EINVAL;
>+-		}
>+-	}
>++	if (ss->header.type < ACPI_PCCT_TYPE_RESERVED)
>++		return 0;
>+ 
>+-	return 0;
>++	return -EINVAL;
>+ }
>+ 
>+ /**
>+@@ -449,8 +440,8 @@ static int __init acpi_pcc_probe(void)
>+ 	struct acpi_table_header *pcct_tbl;
>+ 	struct acpi_subtable_header *pcct_entry;
>+ 	struct acpi_table_pcct *acpi_pcct_tbl;
>++	struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
>+ 	int count, i, rc;
>+-	int sum = 0;
>+ 	acpi_status status = AE_OK;
>+ 
>+ 	/* Search for PCCT */
>+@@ -459,43 +450,41 @@ static int __init acpi_pcc_probe(void)
>+ 	if (ACPI_FAILURE(status) || !pcct_tbl)
>+ 		return -ENODEV;
>+ 
>+-	count = acpi_table_parse_entries(ACPI_SIG_PCCT,
>+-			sizeof(struct acpi_table_pcct),
>+-			ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE,
>+-			parse_pcc_subspace, MAX_PCC_SUBSPACES);
>+-	sum += (count > 0) ? count : 0;
>+-
>+-	count = acpi_table_parse_entries(ACPI_SIG_PCCT,
>+-			sizeof(struct acpi_table_pcct),
>+-			ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2,
>+-			parse_pcc_subspace, MAX_PCC_SUBSPACES);
>+-	sum += (count > 0) ? count : 0;
>++	/* Set up the subtable handlers */
>++	for (i = ACPI_PCCT_TYPE_GENERIC_SUBSPACE;
>++	     i < ACPI_PCCT_TYPE_RESERVED; i++) {
>++		proc[i].id = i;
>++		proc[i].count = 0;
>++		proc[i].handler = parse_pcc_subspace;
>++	}
>+ 
>+-	if (sum == 0 || sum >= MAX_PCC_SUBSPACES) {
>+-		pr_err("Error parsing PCC subspaces from PCCT\n");
>++	count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
>++			sizeof(struct acpi_table_pcct), proc,
>++			ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
>++	if (count == 0 || count > MAX_PCC_SUBSPACES) {
>++		pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
>+ 		return -EINVAL;
>+ 	}
>+ 
>+-	pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) *
>+-			sum, GFP_KERNEL);
>++	pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) * count, GFP_KERNEL);
>+ 	if (!pcc_mbox_channels) {
>+ 		pr_err("Could not allocate space for PCC mbox channels\n");
>+ 		return -ENOMEM;
>+ 	}
>+ 
>+-	pcc_doorbell_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
>++	pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
>+ 	if (!pcc_doorbell_vaddr) {
>+ 		rc = -ENOMEM;
>+ 		goto err_free_mbox;
>+ 	}
>+ 
>+-	pcc_doorbell_ack_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
>++	pcc_doorbell_ack_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
>+ 	if (!pcc_doorbell_ack_vaddr) {
>+ 		rc = -ENOMEM;
>+ 		goto err_free_db_vaddr;
>+ 	}
>+ 
>+-	pcc_doorbell_irq = kcalloc(sum, sizeof(int), GFP_KERNEL);
>++	pcc_doorbell_irq = kcalloc(count, sizeof(int), GFP_KERNEL);
>+ 	if (!pcc_doorbell_irq) {
>+ 		rc = -ENOMEM;
>+ 		goto err_free_db_ack_vaddr;
>+@@ -509,18 +498,24 @@ static int __init acpi_pcc_probe(void)
>+ 	if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
>+ 		pcc_mbox_ctrl.txdone_irq = true;
>+ 
>+-	for (i = 0; i < sum; i++) {
>++	for (i = 0; i < count; i++) {
>+ 		struct acpi_generic_address *db_reg;
>+-		struct acpi_pcct_hw_reduced *pcct_ss;
>++		struct acpi_pcct_subspace *pcct_ss;
>+ 		pcc_mbox_channels[i].con_priv = pcct_entry;
>+ 
>+-		pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry;
>++		if (pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
>++		    pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
>++			struct acpi_pcct_hw_reduced *pcct_hrss;
>++
>++			pcct_hrss = (struct acpi_pcct_hw_reduced *) pcct_entry;
>+ 
>+-		if (pcc_mbox_ctrl.txdone_irq) {
>+-			rc = pcc_parse_subspace_irq(i, pcct_ss);
>+-			if (rc < 0)
>+-				goto err;
>++			if (pcc_mbox_ctrl.txdone_irq) {
>++				rc = pcc_parse_subspace_irq(i, pcct_hrss);
>++				if (rc < 0)
>++					goto err;
>++			}
>+ 		}
>++		pcct_ss = (struct acpi_pcct_subspace *) pcct_entry;
>+ 
>+ 		/* If doorbell is in system memory cache the virt address */
>+ 		db_reg = &pcct_ss->doorbell_register;
>+@@ -531,7 +526,7 @@ static int __init acpi_pcc_probe(void)
>+ 			((unsigned long) pcct_entry + pcct_entry->length);
>+ 	}
>+ 
>+-	pcc_mbox_ctrl.num_chans = sum;
>++	pcc_mbox_ctrl.num_chans = count;
>+ 
>+ 	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
>+ 
>+-- 
>+2.14.3
>+
>diff --git a/kernel.spec b/kernel.spec
>index 943cded5..c2706996 100644
>--- a/kernel.spec
>+++ b/kernel.spec
>@@ -618,6 +618,10 @@ Patch502: input-rmi4-remove-the-need-for-artifical-IRQ.patch
> # rhbz 1509461
> Patch503: v3-2-2-Input-synaptics---Lenovo-X1-Carbon-5-should-use-SMBUS-RMI.patch
> 
>+# rhbz 1435837
>+# https://www.spinics.net/lists/linux-acpi/msg82405.html
>+Patch504: 0001-mailbox-PCC-erroneous-error-message-when-parsing-ACP.patch
>+
> # END OF PATCH DEFINITIONS
> 
> %endif
>-- 
>2.14.3
>

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Attachments on bug 1435837: 1287515 | 1410351 | 1410352 | 1410772 | 1413946 | 1413947 | 1417469 | 1417475 | 1417476 | 1425543 | 1425544 | 1441175