From: Ethan Zhao <haifeng.zhao@intel.com>
To: bhelgaas@google.com, oohall@gmail.com, ruscur@russell.cc,
lukas@wunner.de, andriy.shevchenko@linux.intel.com,
stuart.w.hayes@gmail.com, mr.nuke.me@gmail.com,
mika.westerberg@linux.intel.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
ashok.raj@linux.intel.com, sathyanarayanan.kuppuswamy@intel.com,
xerces.zhao@gmail.com, Ethan Zhao <haifeng.zhao@intel.com>
Subject: [PATCH v8 4/6] PCI/ERR: simplify function pci_dev_set_io_state() with if
Date: Wed, 7 Oct 2020 07:31:56 -0400 [thread overview]
Message-ID: <20201007113158.48933-5-haifeng.zhao@intel.com> (raw)
In-Reply-To: <20201007113158.48933-1-haifeng.zhao@intel.com>
No function change.
Signed-off-by: Ethan Zhao <haifeng.zhao@intel.com>
---
Changes:
v8: based on Bjorn's code and truth table, simplify the logic of
function pci_dev_set_io_state(), no function change.
drivers/pci/pci.h | 54 ++++++++++++++++++++---------------------------
1 file changed, 23 insertions(+), 31 deletions(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 455b32187abd..bceb3f108744 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -359,39 +359,31 @@ struct pci_sriov {
static inline bool pci_dev_set_io_state(struct pci_dev *dev,
pci_channel_state_t new)
{
- bool changed = false;
-
device_lock_assert(&dev->dev);
- switch (new) {
- case pci_channel_io_perm_failure:
- switch (dev->error_state) {
- case pci_channel_io_frozen:
- case pci_channel_io_normal:
- case pci_channel_io_perm_failure:
- changed = true;
- break;
- }
- break;
- case pci_channel_io_frozen:
- switch (dev->error_state) {
- case pci_channel_io_frozen:
- case pci_channel_io_normal:
- changed = true;
- break;
- }
- break;
- case pci_channel_io_normal:
- switch (dev->error_state) {
- case pci_channel_io_frozen:
- case pci_channel_io_normal:
- changed = true;
- break;
- }
- break;
+/*
+ * Truth table:
+ * requested new state
+ * current ------------------------------------------
+ * state normal frozen perm_failure
+ * ------------ + ------------- ------------- ------------
+ * normal | normal frozen perm_failure
+ * frozen | normal frozen perm_failure
+ * perm_failure | perm_failure* perm_failure* perm_failure
+ */
+
+ /* Can always put a device in perm_failure state */
+ if (new == pci_channel_io_perm_failure) {
+ dev->error_state = pci_channel_io_perm_failure;
+ return true;
}
- if (changed)
- dev->error_state = new;
- return changed;
+
+ /* If already in perm_failure, can't set to normal or frozen */
+ if (dev->error_state == pci_channel_io_perm_failure)
+ return false;
+
+ /* Can always change normal to frozen or vice versa */
+ dev->error_state = new;
+ return true;
}
static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
--
2.18.4
next prev parent reply other threads:[~2020-10-07 11:33 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 11:31 [PATCH v8 0/6] Fix DPC hotplug race and enhance error handling Ethan Zhao
2020-10-07 11:31 ` [PATCH v8 1/6] PCI/ERR: get device before call device driver to avoid NULL pointer dereference Ethan Zhao
2020-10-07 17:24 ` Kuppuswamy, Sathyanarayanan
2020-10-08 5:38 ` Ethan Zhao
2020-10-07 11:31 ` [PATCH v8 2/6] PCI/DPC: define a function to check and wait till port finish DPC handling Ethan Zhao
2020-10-07 17:28 ` Kuppuswamy, Sathyanarayanan
2020-10-08 5:49 ` Ethan Zhao
2020-10-09 3:16 ` Ethan Zhao
2020-10-07 11:31 ` [PATCH v8 3/6] PCI: pciehp: check and wait port status out of DPC before handling DLLSC and PDC Ethan Zhao
2020-10-07 11:31 ` Ethan Zhao [this message]
2020-10-07 11:31 ` [PATCH v8 5/6] PCI/ERR: only return true when dev io state is really changed Ethan Zhao
2020-10-07 11:31 ` [PATCH v8 6/6] PCI/ERR: don't mix io state not changed and no driver together Ethan Zhao
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