fix: read GPU VRAM via DRM sysfs vram_size fallback by GongHeng2017 · Pull Request #964 · linuxdeepin/deepin-devicemanager

GongHeng2017 · 2026-11-05T12:58:26Z

fix: read GPU VRAM via DRM sysfs vram_size fallback

Root cause: radeon driver does not expose VRAM size through
hwinfo, leaving m_GraphicsMemory empty for Turks HD 7600 GPU
Fix: when m_GraphicsMemory is empty, match PCI BDF against
/sys/class/drm/card*/device symlinks and read vram_size file,
convert to GB (>=1024 MB) or MB
Impact: only triggers when existing amdgpu/hwinfo paths yield
empty memory, no regression for GPUs already reporting VRAM

Log: GPU VRAM size now displayed for radeon GPUs via DRM sysfs

Influence:

Verify VRAM displays for radeon GPU (Turks HD 7600)
Verify amdgpu GPUs still show VRAM correctly
Verify multi-GPU systems match correct card by PCI BDF

PMS: BUG-380847

Migrate from develop/eagle PR #959 to master.

Summary by Sourcery

Bug Fixes:

Add a DRM sysfs fallback to report GPU VRAM for devices whose existing hardware information sources provide no memory value.

sourcery-ai · 2026-11-05T12:58:43Z

Reviewer's Guide

When hwinfo/amdgpu detection leaves VRAM unset, the GPU device code now identifies the corresponding DRM card by PCI BDF and reads its sysfs vram_size, while preserving existing reporting paths and formatting the fallback value in GB or MB.

Sequence diagram for DRM sysfs VRAM fallback

sequenceDiagram
    participant GPU as DeviceGpu
    participant Hwinfo as hwinfo/amdgpu
    participant DRM as DRM sysfs
    participant File as vram_size

    GPU->>Hwinfo: setHwinfoInfo(mapInfo)
    alt m_GraphicsMemory is not empty
        Hwinfo-->>GPU: Existing VRAM value
    else m_GraphicsMemory is empty
        GPU->>GPU: Extract PCI BDF from m_SysPath
        GPU->>DRM: Enumerate /sys/class/drm/card[0-9]*
        DRM-->>GPU: Card directories
        GPU->>DRM: Resolve card/device symlink
        alt PCI BDF matches
            GPU->>File: Read card/device/vram_size
            File-->>GPU: VRAM size in MB
            GPU->>GPU: Format value as GB or MB
        end
    end

File-Level Changes

Change	Details	Files
Add a DRM sysfs fallback for GPU VRAM detection when existing hardware-information data is unavailable.	Extract the GPU PCI BDF from the device sysfs path. Enumerate DRM card directories and skip connector entries. Match the GPU to its DRM card through the device symlink target. Read and parse vram_size, formatting values in GB or MB based on size.	`deepin-devicemanager/src/DeviceManager/DeviceGpu.cpp`

Tips and commands

Interacting with Sourcery

Trigger a new review: Comment @sourcery-ai review on the pull request.
Continue discussions: Reply directly to Sourcery's review comments.
Generate a GitHub issue from a review comment: Ask Sourcery to create an
issue from a review comment by replying to it. You can also reply to a
review comment with @sourcery-ai issue to create an issue from it.
Generate a pull request title: Write @sourcery-ai anywhere in the pull
request title to generate a title at any time. You can also comment
@sourcery-ai title on the pull request to (re-)generate the title at any time.
Generate a pull request summary: Write @sourcery-ai summary anywhere in
the pull request body to generate a PR summary at any time exactly where you
want it. You can also comment @sourcery-ai summary on the pull request to
(re-)generate the summary at any time.
Generate reviewer's guide: Comment @sourcery-ai guide on the pull
request to (re-)generate the reviewer's guide at any time.
Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
pull request to resolve all Sourcery comments. Useful if you've already
addressed all the comments and don't want to see them anymore.
Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
request to dismiss all existing Sourcery reviews. Especially useful if you
want to start fresh with a new review - don't forget to comment
@sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

Enable or disable review features such as the Sourcery-generated pull request
summary, the reviewer's guide, and others.
Change the review language.
Add, remove or edit custom review instructions.
Adjust other review settings.

Getting Help

Contact our support team for questions or feedback.
Visit our documentation for detailed guides and information.
Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.

sourcery-ai

Hey - I've found 2 issues

Prompt for AI Agents

Please address the comments from this code review:

## Individual Comments

### Comment 1
<location path="deepin-devicemanager/src/DeviceManager/DeviceGpu.cpp" line_range="247-249" />
<code_context>
+                    memFile.close();
+                    bool ok;
+                    quint64 vramMB = memStr.toULongLong(&ok);
+                    if (ok && vramMB >= 1024) {
+                        m_GraphicsMemory = QString::number(vramMB / 1024) + "GB";
+                    } else {
+                        m_GraphicsMemory = QString::number(vramMB) + "MB";
+                    }
</code_context>
<issue_to_address>
**VRAM capacities are vastly overstated**

When the DRM fallback reads a valid `vram_size` value, `vram_size` reports bytes, but the fallback treats the value as megabytes and divides by only 1024 for GB (or labels the raw bytes as MB), so a multi-GiB GPU is displayed with a vastly overstated capacity.

Convert the byte count to the intended unit before formatting the capacity.
</issue_to_address>

### Comment 2
<location path="deepin-devicemanager/src/DeviceManager/DeviceGpu.cpp" line_range="242-254" />
<code_context>
+                if (!devicePath.contains(pciBdf))
+                    continue;
+                QFile memFile(QString("/sys/class/drm/%1/device/vram_size").arg(card));
+                if (memFile.open(QIODevice::ReadOnly)) {
+                    QString memStr = memFile.readAll().trimmed();
+                    memFile.close();
+                    bool ok;
+                    quint64 vramMB = memStr.toULongLong(&ok);
+                    if (ok && vramMB >= 1024) {
+                        m_GraphicsMemory = QString::number(vramMB / 1024) + "GB";
+                    } else {
+                        m_GraphicsMemory = QString::number(vramMB) + "MB";
+                    }
+                    break;
+                }
</code_context>
<issue_to_address>
**Fallback failures are invisible**

When the DRM card cannot be matched to the PCI BDF or its `vram_size` file cannot be opened, a failed file open or unmatched DRM card leaves `m_GraphicsMemory` empty without a diagnostic. `setHwinfoInfo` still returns true, so the caller adds the GPU and operators see missing memory without knowing why the fallback failed.

Log when the fallback cannot find a matching card or read its VRAM file.
</issue_to_address>

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

sourcery-ai · 2026-11-05T13:01:31Z

+                    if (ok && vramMB >= 1024) {
+                        m_GraphicsMemory = QString::number(vramMB / 1024) + "GB";
+                    } else {


🟠 High · VRAM capacities are vastly overstated

When the DRM fallback reads a valid vram_size value, vram_size reports bytes, but the fallback treats the value as megabytes and divides by only 1024 for GB (or labels the raw bytes as MB), so a multi-GiB GPU is displayed with a vastly overstated capacity.

Convert the byte count to the intended unit before formatting the capacity.

Prompt for AI agents

In `deepin-devicemanager/src/DeviceManager/DeviceGpu.cpp` at lines 247-249: **VRAM capacities are vastly overstated** When the DRM fallback reads a valid `vram_size` value, `vram_size` reports bytes, but the fallback treats the value as megabytes and divides by only 1024 for GB (or labels the raw bytes as MB), so a multi-GiB GPU is displayed with a vastly overstated capacity. Convert the byte count to the intended unit before formatting the capacity.

sourcery-ai · 2026-11-05T13:01:31Z

+                if (memFile.open(QIODevice::ReadOnly)) {
+                    QString memStr = memFile.readAll().trimmed();
+                    memFile.close();
+                    bool ok;
+                    quint64 vramMB = memStr.toULongLong(&ok);
+                    if (ok && vramMB >= 1024) {
+                        m_GraphicsMemory = QString::number(vramMB / 1024) + "GB";
+                    } else {
+                        m_GraphicsMemory = QString::number(vramMB) + "MB";
+                    }
+                    break;
+                }
+            }


⚪ Low · Fallback failures are invisible

When the DRM card cannot be matched to the PCI BDF or its vram_size file cannot be opened, a failed file open or unmatched DRM card leaves m_GraphicsMemory empty without a diagnostic. setHwinfoInfo still returns true, so the caller adds the GPU and operators see missing memory without knowing why the fallback failed.

Log when the fallback cannot find a matching card or read its VRAM file.

Prompt for AI agents

In `deepin-devicemanager/src/DeviceManager/DeviceGpu.cpp` at lines 242-254: **Fallback failures are invisible** When the DRM card cannot be matched to the PCI BDF or its `vram_size` file cannot be opened, a failed file open or unmatched DRM card leaves `m_GraphicsMemory` empty without a diagnostic. `setHwinfoInfo` still returns true, so the caller adds the GPU and operators see missing memory without knowing why the fallback failed. Log when the fallback cannot find a matching card or read its VRAM file.

1. Root cause: radeon driver does not expose VRAM size through hwinfo, leaving m_GraphicsMemory empty for Turks HD 7600 GPU 2. Fix: when m_GraphicsMemory is empty, match PCI BDF against /sys/class/drm/card*/device symlinks and read vram_size file, convert to GB (>=1024 MB) or MB 3. Impact: only triggers when existing amdgpu/hwinfo paths yield empty memory, no regression for GPUs already reporting VRAM Log: GPU VRAM size now displayed for radeon GPUs via DRM sysfs Influence: 1. Verify VRAM displays for radeon GPU (Turks HD 7600) 2. Verify amdgpu GPUs still show VRAM correctly 3. Verify multi-GPU systems match correct card by PCI BDF Bug: #380847 Task: #398195 Migrate from develop/eagle PR linuxdeepin#959 to master.

deepin-ci-robot · 2026-11-06T02:11:13Z

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: add-uos, GongHeng2017, lzwind

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

debian/deepin/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

GongHeng2017 · 2026-11-06T02:13:57Z

/merge

sourcery-ai Bot reviewed Nov 5, 2026

View reviewed changes

GongHeng2017 force-pushed the agent/uos-pmo/ddd670883772 branch from 22a1154 to 370c5af Compare November 5, 2026 13:55

GongHeng2017 force-pushed the agent/uos-pmo/ddd670883772 branch from 370c5af to 197dd29 Compare November 6, 2026 01:30

add-uos approved these changes Nov 6, 2026

View reviewed changes

lzwind approved these changes Nov 6, 2026

View reviewed changes

deepin-bot Bot merged commit d11f499 into linuxdeepin:master Nov 6, 2026
17 checks passed

Navigation Menu

Repository navigation

fix: read GPU VRAM via DRM sysfs vram_size fallback - #964

fix: read GPU VRAM via DRM sysfs vram_size fallback#964
deepin-bot[bot] merged 1 commit into
linuxdeepin:masterfrom
GongHeng2017:agent/uos-pmo/ddd670883772

GongHeng2017 commented Nov 5, 2026 •

edited by sourcery-ai Bot

Loading

Uh oh!

sourcery-ai Bot commented Nov 5, 2026

Interacting with Sourcery

Customizing Your Experience

Getting Help

Uh oh!

sourcery-ai Bot left a comment

Uh oh!

sourcery-ai Bot Nov 5, 2026

Uh oh!

sourcery-ai Bot Nov 5, 2026

Uh oh!

deepin-ci-robot commented Nov 6, 2026

Uh oh!

GongHeng2017 commented Nov 6, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Conversation

GongHeng2017 commented Nov 5, 2026 • edited by sourcery-ai Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary by Sourcery

Uh oh!

sourcery-ai Bot commented Nov 5, 2026

Reviewer's Guide

Sequence diagram for DRM sysfs VRAM fallback

File-Level Changes

Interacting with Sourcery

Customizing Your Experience

Getting Help

Uh oh!

sourcery-ai Bot left a comment

Choose a reason for hiding this comment

Uh oh!

sourcery-ai Bot Nov 5, 2026

Choose a reason for hiding this comment

Uh oh!

sourcery-ai Bot Nov 5, 2026

Choose a reason for hiding this comment

Uh oh!

deepin-ci-robot commented Nov 6, 2026

Uh oh!

GongHeng2017 commented Nov 6, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

GongHeng2017 commented Nov 5, 2026 •

edited by sourcery-ai Bot

Loading