msm-gbm-backend: rename GBM backend library from msm_gbm to msm-kms_gbm#1679
msm-gbm-backend: rename GBM backend library from msm_gbm to msm-kms_gbm#1679yashgupta2126 wants to merge 1 commit intoqualcomm-linux:masterfrom
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| requiring GBM_BACKEND env var to be set explicitly. | ||
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| Signed-off-by: Yash Gupta <quic_ygupt@quicinc.com> | ||
| Upstream-Status: Pending |
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Why are we patching a repository we maintain?
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The repository is shared between ubuntu deliverable in 6.8 kernel and mainline deliverable in 6.18+ kernel. The driver's name has changed with 'commit id 217ed15bd399980981f90f4332bc7ad4b05baa7e' in latest kernel version. Thus, raising a patch for mainline
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Hm, NAK from my side, mainline should contain the latest changes as part of the repo (as part of a mainline / master / trunk branch), if we need to use an older rev / branch for ubuntu, then manage that separately.
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Remember this will also later be used with debian and other distros (@lool fyi).
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This is wrong. The driver name wasn't changed. Instead a new driver name has been added. We need to support both.
The MSM DRM subsystem now exposes two driver names: - 'msm' : legacy combined GPU+KMS driver (DRIVER_FEATURES_GPU | KMS) - 'msm-kms' : new KMS-only driver used Mesa's GBM backend auto-detection looks for '<drm_driver_name>_gbm.so' in the GBM backends path. With only 'msm_gbm.so' installed, platforms using the 'msm-kms' driver cannot find the backend and fall back to the generic 'dri' backend, causing GBM surface creation to fail. Build the library as 'msm-kms_gbm.so' and install a compatibility symlink 'msm_gbm.so -> msm-kms_gbm.so' so that both driver names resolve to the same MSM GBM backend: /usr/lib/gbm/msm-kms_gbm.so (for 'msm-kms' driver) /usr/lib/gbm/msm_gbm.so -> msm-kms_gbm.so (for 'msm' driver) Signed-off-by: Yash Gupta <quic_ygupt@quicinc.com>
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NAK for the pending patch. Get it merged to the repo.
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The DRM driver name was updated from 'msm' to 'msm-kms'. Mesa's GBM backend selection uses the DRM driver name to auto-discover the backend library by looking for '<drm_driver_name>_gbm.so' in GBM_BACKENDS_PATH or the default path (/usr/lib/gbm/).
With the old library name 'msm_gbm.so', Mesa cannot find the backend for driver 'msm-kms' and silently falls back to the generic 'dri' backend
Rename the library to 'msm-kms_gbm.so' so that Mesa's auto-detection picks the correct MSM GBM backend without requiring the GBM_BACKEND environment variable to be set explicitly.
KERNEL Commit ID for reference: - 217ed15bd399980981f90f4332bc7ad4b05baa7e