From: lirongqing <lirongqing@baidu.com>
To: "Ryder Lee" <ryder.lee@mediatek.com>,
"Jianjun Wang" <jianjun.wang@mediatek.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
"Manivannan Sadhasivam" <mani@kernel.org>,
"Rob Herring" <robh@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"AngeloGioacchino Del Regno"
<angelogioacchino.delregno@collabora.com>,
linux-pci@vger.kernel.org, linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Cc: Li RongQing <lirongqing@baidu.com>
Subject: [PATCH] PCI: mediatek: Fix operator precedence in PCIE_FTS_NUM_L0 macro
Date: Thu, 14 May 2026 20:55:52 -0400 [thread overview]
Message-ID: <20260515005552.2343-1-lirongqing@baidu.com> (raw)
From: Li RongQing <lirongqing@baidu.com>
The original PCIE_FTS_NUM_L0(x) macro was buggy due to improper operator
precedence, where ((x) & 0xff << 8) was evaluated as ((x) & 0xff00).
Instead of just fixing the parentheses, use the standard FIELD_PREP()
macro. This makes the code more robust by automatically handling masks
and shifts, while also adding compile-time type and range checking to
ensure the value fits within PCIE_FTS_NUM_MASK.
Fixes: 637cfacae96f ("PCI: mediatek: Add MediaTek PCIe host controller support")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
drivers/pci/controller/pcie-mediatek.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index 7572252..00f0e29 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -61,7 +61,7 @@
/* MediaTek specific configuration registers */
#define PCIE_FTS_NUM 0x70c
#define PCIE_FTS_NUM_MASK GENMASK(15, 8)
-#define PCIE_FTS_NUM_L0(x) ((x) & 0xff << 8)
+#define PCIE_FTS_NUM_L0(x) FIELD_PREP(PCIE_FTS_NUM_MASK, x)
#define PCIE_FC_CREDIT 0x73c
#define PCIE_FC_CREDIT_MASK (GENMASK(31, 31) | GENMASK(28, 16))
--
2.9.4
next reply other threads:[~2026-05-15 2:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-15 0:55 lirongqing [this message]
2026-05-15 1:27 ` [PATCH] PCI: mediatek: Fix operator precedence in PCIE_FTS_NUM_L0 macro Krzysztof Wilczyński
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=20260515005552.2343-1-lirongqing@baidu.com \
--to=lirongqing@baidu.com \
--cc=angelogioacchino.delregno@collabora.com \
--cc=bhelgaas@google.com \
--cc=jianjun.wang@mediatek.com \
--cc=kwilczynski@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=mani@kernel.org \
--cc=matthias.bgg@gmail.com \
--cc=robh@kernel.org \
--cc=ryder.lee@mediatek.com \
/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