From c1e7254935c0414e7a31737bd357872d1b0f346b Mon Sep 17 00:00:00 2001 From: Taotao Chen Date: Fri, 22 Aug 2025 03:06:59 +0000 Subject: [PATCH 1/2] drm/i915: set O_LARGEFILE in __create_shmem() Without O_LARGEFILE, file->f_op->write_iter calls generic_write_check_limits(), which enforces a 2GB (MAX_NON_LFS) limit, causing -EFBIG on large writes. In shmem_pwrite(), this error is later masked as -EIO due to the error handling order, leading to igt failures like gen9_exec_parse(bb-large). Set O_LARGEFILE in __create_shmem() to prevent -EFBIG on large writes. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202508081029.343192ec-lkp@intel.com Fixes: 048832a3f400 ("drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter") Signed-off-by: Taotao Chen Reviewed-by: Andi Shyti Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20250822030651.28099-1-chentaotao@didiglobal.com (cherry picked from commit e296a2266c572a7537e638b0dbbfc66d11df46f9) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index e3d188455f67..b9dae15c1d16 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -514,6 +514,13 @@ static int __create_shmem(struct drm_i915_private *i915, if (IS_ERR(filp)) return PTR_ERR(filp); + /* + * Prevent -EFBIG by allowing large writes beyond MAX_NON_LFS on shmem + * objects by setting O_LARGEFILE. + */ + if (force_o_largefile()) + filp->f_flags |= O_LARGEFILE; + obj->filp = filp; return 0; } From 7f97a0a871d9532f2e1a5ee7d16d0e364215bcac Mon Sep 17 00:00:00 2001 From: Suraj Kandpal Date: Mon, 8 Sep 2025 09:52:08 +0530 Subject: [PATCH 2/2] drm/i915/ddi: Guard reg_val against a INVALID_TRANSCODER Currently we check if the encoder is INVALID or -1 and throw a WARN_ON but we still end up writing the temp value which will overflow and corrupt the whole programmed value. --v2 -Assign a bogus transcoder to master in case we get a INVALID TRANSCODER [Jani] Fixes: 6671c367a9bea ("drm/i915/tgl: Select master transcoder for MST stream") Signed-off-by: Suraj Kandpal Reviewed-by: Jani Nikula Link: https://lore.kernel.org/r/20250908042208.1011144-1-suraj.kandpal@intel.com (cherry picked from commit c8e8e9ab14a6ea926641d161768e1e3ef286a853) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/display/intel_ddi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 0405396c7750..9ecbb4b99c37 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -596,8 +596,9 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder, enum transcoder master; master = crtc_state->mst_master_transcoder; - drm_WARN_ON(display->drm, - master == INVALID_TRANSCODER); + if (drm_WARN_ON(display->drm, + master == INVALID_TRANSCODER)) + master = TRANSCODER_A; temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master); } } else {