public inbox for linux-tegra@vger.kernel.org
 help / color / mirror / Atom feed
From: Manikanta Maddireddy <mmaddireddy@nvidia.com>
To: <bhelgaas@google.com>, <lpieralisi@kernel.org>,
	<kwilczynski@kernel.org>, <mani@kernel.org>, <robh@kernel.org>,
	<krzk+dt@kernel.org>, <conor+dt@kernel.org>,
	<thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
	<kishon@kernel.org>, <arnd@arndb.de>,
	<gregkh@linuxfoundation.org>, <Frank.Li@nxp.com>,
	<den@valinux.co.jp>, <hongxing.zhu@nxp.com>,
	<jingoohan1@gmail.com>, <vidyas@nvidia.com>, <cassel@kernel.org>,
	<18255117159@163.com>
Cc: <linux-pci@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	Manikanta Maddireddy <mmaddireddy@nvidia.com>,
	kernel test robot <lkp@intel.com>
Subject: [PATCH 1/1] PCI: tegra194: fix min() signedness when capping ASPM L1 entrance latency
Date: Tue, 7 Apr 2026 20:27:49 +0530	[thread overview]
Message-ID: <20260407145749.130753-1-mmaddireddy@nvidia.com> (raw)

The DT property "aspm-l1-entry-delay-ns" is converted to microseconds,
then encoded for the L1 entrance latency register field as ilog2(us) + 1,
clamped to the hardware maximum of 7.

ilog2() returns int type, while the upper bound is 7U (unsigned int).
The min() macro is implemented with __careful_cmp(), which rejects mixed
signed and unsigned operands at compile time via BUILD_BUG_ON_MSG in
minmax.h; that check trips on this pair, notably when building with W=1.

This combination fails to build (e.g. parisc allyesconfig, GCC 15, as
reported by the 0-day bot).

Use min_t(u32, ilog2(us) + 1U, 7U) so both sides of the comparison are
unsigned and consistent with aspm_l1_enter_lat.

Fixes: 4a44cd65c9dd ("PCI: tegra194: Use aspm-l1-entry-delay-ns DT property for L1 entrance latency")
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202604051407.AODe3ddZ-lkp@intel.com/
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 393f75ce3df3..93d3452ac117 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1147,7 +1147,7 @@ static int tegra_pcie_dw_parse_dt(struct tegra_pcie_dw *pcie)
 	if (!ret) {
 		u32 us = max(val / 1000, 1U);
 
-		pcie->aspm_l1_enter_lat = min(ilog2(us) + 1, 7U);
+		pcie->aspm_l1_enter_lat = min_t(u32, ilog2(us) + 1U, 7U);
 	}
 
 	ret = of_property_read_u32(np, "num-lanes", &pcie->num_lanes);
-- 
2.34.1


             reply	other threads:[~2026-04-07 14:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-07 14:57 Manikanta Maddireddy [this message]
2026-04-08  5:57 ` [PATCH 1/1] PCI: tegra194: fix min() signedness when capping ASPM L1 entrance latency Manikanta Maddireddy
2026-04-09 16:55   ` Manivannan Sadhasivam
2026-04-08 11:58 ` David Laight
2026-04-09  7:05   ` Manikanta Maddireddy
2026-04-09 16:53     ` Manivannan Sadhasivam

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=20260407145749.130753-1-mmaddireddy@nvidia.com \
    --to=mmaddireddy@nvidia.com \
    --cc=18255117159@163.com \
    --cc=Frank.Li@nxp.com \
    --cc=arnd@arndb.de \
    --cc=bhelgaas@google.com \
    --cc=cassel@kernel.org \
    --cc=conor+dt@kernel.org \
    --cc=den@valinux.co.jp \
    --cc=gregkh@linuxfoundation.org \
    --cc=hongxing.zhu@nxp.com \
    --cc=jingoohan1@gmail.com \
    --cc=jonathanh@nvidia.com \
    --cc=kishon@kernel.org \
    --cc=krzk+dt@kernel.org \
    --cc=kwilczynski@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=lkp@intel.com \
    --cc=lpieralisi@kernel.org \
    --cc=mani@kernel.org \
    --cc=robh@kernel.org \
    --cc=thierry.reding@gmail.com \
    --cc=vidyas@nvidia.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