From: Naveen Naidu <naveennaidu479@gmail.com>
To: bhelgaas@google.com
Cc: "open list:PCI ENHANCED ERROR HANDLING EEH FOR POWERPC"
<linuxppc-dev@lists.ozlabs.org>,
linux-pci@vger.kernel.org, skhan@linuxfoundation.org,
linux-kernel@vger.kernel.org,
Naveen Naidu <naveennaidu479@gmail.com>,
Oliver O'Halloran <oohall@gmail.com>,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: [PATCH v4 19/25] PCI/DPC: Use PCI_POSSIBLE_ERROR() to check read from hardware
Date: Thu, 18 Nov 2021 19:33:29 +0530 [thread overview]
Message-ID: <9b0632f1f183432149f495cf12bdd5a72cc597a4.1637243717.git.naveennaidu479@gmail.com> (raw)
In-Reply-To: <cover.1637243717.git.naveennaidu479@gmail.com>
An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error. There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.
Use PCI_POSSIBLE_ERROR() to check the response we get when we read
data from hardware.
This helps unify PCI error response checking and make error checks
consistent and easier to find.
Compile tested only.
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
drivers/pci/pcie/dpc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index c556e7beafe3..3e9afee02e8d 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -79,7 +79,7 @@ static bool dpc_completed(struct pci_dev *pdev)
u16 status;
pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status);
- if ((status != 0xffff) && (status & PCI_EXP_DPC_STATUS_TRIGGER))
+ if ((!PCI_POSSIBLE_ERROR(status)) && (status & PCI_EXP_DPC_STATUS_TRIGGER))
return false;
if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags))
@@ -312,7 +312,7 @@ static irqreturn_t dpc_irq(int irq, void *context)
pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
- if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0))
+ if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || PCI_POSSIBLE_ERROR(status))
return IRQ_NONE;
pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
--
2.25.1
next prev parent reply other threads:[~2021-11-18 14:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-18 14:03 [PATCH v4 00/25] Unify PCI error response checking Naveen Naidu
2021-11-18 14:03 ` Naveen Naidu [this message]
2021-11-18 20:44 ` Bjorn Helgaas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=9b0632f1f183432149f495cf12bdd5a72cc597a4.1637243717.git.naveennaidu479@gmail.com \
--to=naveennaidu479@gmail.com \
--cc=bhelgaas@google.com \
--cc=linux-kernel-mentees@lists.linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=oohall@gmail.com \
--cc=skhan@linuxfoundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).