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Srinivasan Shanmugam
dc915275ea
If the parent is NULL, adev->pdev is used to retrieve the PCIe speed and
width, ensuring that the function can still determine these
capabilities from the device itself.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:6193 amdgpu_device_gpu_bandwidth()
error: we previously assumed 'parent' could be null (see line 6180)
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
6170 static void amdgpu_device_gpu_bandwidth(struct amdgpu_device *adev,
6171 enum pci_bus_speed *speed,
6172 enum pcie_link_width *width)
6173 {
6174 struct pci_dev *parent = adev->pdev;
6175
6176 if (!speed || !width)
6177 return;
6178
6179 parent = pci_upstream_bridge(parent);
6180 if (parent && parent->vendor == PCI_VENDOR_ID_ATI) {
^^^^^^
If parent is NULL
6181 /* use the upstream/downstream switches internal to dGPU */
6182 *speed = pcie_get_speed_cap(parent);
6183 *width = pcie_get_width_cap(parent);
6184 while ((parent = pci_upstream_bridge(parent))) {
6185 if (parent->vendor == PCI_VENDOR_ID_ATI) {
6186 /* use the upstream/downstream switches internal to dGPU */
6187 *speed = pcie_get_speed_cap(parent);
6188 *width = pcie_get_width_cap(parent);
6189 }
6190 }
6191 } else {
6192 /* use the device itself */
--> 6193 *speed = pcie_get_speed_cap(parent);
^^^^^^ Then we are toasted here.
6194 *width = pcie_get_width_cap(parent);
6195 }
6196 }
Fixes: 757e8b951c ("drm/amdgpu: cache gpu pcie link width")
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.