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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spamd-Result: default: False [-4.29 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; FUZZY_BLOCKED(0.00)[rspamd.com]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FREEMAIL_TO(0.00)[nxp.com,oss.nxp.com,linux.intel.com,kernel.org,gmail.com,ffwll.ch,redhat.com]; TO_DN_EQ_ADDR_SOME(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; RCPT_COUNT_SEVEN(0.00)[9]; MID_RHS_MATCH_FROM(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo] X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Am 11.06.24 um 10:23 schrieb Peng Fan: >> Subject: Re: [PATCH] drm/fbdev-dma: fix getting smem_start >> >> Hi >> >> Am 11.06.24 um 03:00 schrieb Peng Fan: >>>> Subject: Re: [PATCH] drm/fbdev-dma: fix getting smem_start >>>> >>>> Hi >>>> >>>> Am 04.06.24 um 10:03 schrieb Peng Fan (OSS): >>>>> From: Peng Fan >>>>> >>>>> If 'info->screen_buffer' locates in vmalloc address space, >>>>> virt_to_page will not be able to get correct results. With >>>>> CONFIG_DEBUG_VM and CONFIG_DEBUG_VIRTUAL enabled on ARM64, >>>> there is dump below: >>>> >>>> Which graphics driver triggers this bug? >>> It is NXP i.MX95 DPU driver which is still in NXP downstream repo. >> Which DRM memory manager does that driver use? > DRM_GEM_DMA_DRIVER_OPS So fbdev-dma would be correct. But with the gem-dma allocator, wouldn't you allocate from one of these dma_alloc_() calls at [1] ? How does the drivers end up with vmalloc'd fbdev memory? Specifically in the light of the docs at [2]. [1] https://elixir.bootlin.com/linux/v6.9/source/drivers/gpu/drm/drm_gem_dma_helper.c#L146 [2] https://elixir.bootlin.com/linux/v6.9/source/Documentation/core-api/dma-api-howto.rst#L124 Best regards Thomas > >> I'm asking because if the driver allocates BOs via vmalloc(), should it really >> use fbdev-dma? > We use it for fbdev emulation. If drm_kms_helper.fbdev_emulation is 0, > fbdev emulation could be disabled. > > Thanks > Peng >> Best regards >> Thomas >> >>> Thanks, >>> Peng. >> -- >> -- >> Thomas Zimmermann >> Graphics Driver Developer >> SUSE Software Solutions Germany GmbH >> Frankenstrasse 146, 90461 Nuernberg, Germany >> GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB >> 36809 (AG Nuernberg) -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)