On 02.12.2025 15:15, Rob Herring wrote: > On Thu, Nov 27, 2025 at 8:28 AM Marek Szyprowski > <[email protected]> wrote: >> On 24.11.2025 19:27, Rob Herring (Arm) wrote: >>> Use the newly added of_reserved_mem_region_to_resource() and >>> of_reserved_mem_region_count() functions to handle "memory-region" >>> properties. >>> >>> The error handling is a bit different in some cases. Often >>> "memory-region" is optional, so failed lookup is not an error. But then >>> an error in of_reserved_mem_lookup() is treated as an error. However, >>> that distinction is not really important. Either the region is available >>> and usable or it is not. So now, it is just >>> of_reserved_mem_region_to_resource() which is checked for an error. >>> >>> Signed-off-by: Rob Herring (Arm) <[email protected]> >> This patch landed in today's linux-next as commit c70b9d5fdcd7 >> ("remoteproc: qcom: Use of_reserved_mem_region_* functions for >> "memory-region""). In my tests I found that it breaks booting of >> DragonBoard410c (arch/arm64/boot/dts/qcom/apq8016-sbc.dts) by causing >> the NULL pointer dereference. The issue is caused by replacing >> devm_ioremap_wc() with devm_ioremap_resource_wc(), which fails on >> devm_request_mem_region(), see comment in the code below. It looks that >> the error handling is somewhere broken. Here is the the kernel log: >> >> remoteproc remoteproc0: 4080000.remoteproc is available >> qcom-wcnss-pil a204000.remoteproc: error -EBUSY: can't request region >> for resource [mem 0x8e200000-0x8e7fffff] >> remoteproc remoteproc1: a204000.remoteproc is available >> remoteproc remoteproc1: powering up a204000.remoteproc >> remoteproc remoteproc1: Booting fw image qcom/apq8016/wcnss.mbn, size >> 4111376 >> Unable to handle kernel paging request at virtual address fffffffffffffff0 >> Mem abort info: >> ... >> Internal error: Oops: 0000000096000046 [#1] SMP >> Modules linked in: cpufreq_powersave qcom_wcnss_pil cpufreq_conservative >> coresight_stm coresight_replicator coresight_tmc coresight_tpiu stm_core >> coresight_funnel coresight_cpu_debug coresight_cti(+) adv7511 coresight >> nfc rfkill msm snd_soc_lpass_apq8016 snd_soc_apq8016_sbc >> snd_soc_lpass_cpu snd_soc_msm8916_analog snd_soc_msm8916_digital >> snd_soc_qcom_common snd_soc_lpass_platform snd_soc_core qrtr ubwc_config >> snd_compress llcc_qcom snd_pcm_dmaengine qcom_q6v5_mss snd_pcm ocmem >> qcom_pil_info qcom_spmi_vadc qcom_camss drm_gpuvm qcom_pon rtc_pm8xxx >> qcom_q6v5 qcom_spmi_temp_alarm venus_core qcom_vadc_common snd_timer >> drm_exec qcom_sysmon snd qcom_common gpu_sched videobuf2_dma_sg >> v4l2_mem2mem qcom_glink_smem v4l2_fwnode soundcore drm_dp_aux_bus >> qmi_helpers mdt_loader v4l2_async videobuf2_memops videobuf2_v4l2 >> videodev qnoc_msm8916 videobuf2_common qcom_rng drm_display_helper mc >> qcom_stats rpmsg_ctrl rpmsg_char display_connector ramoops socinfo >> rmtfs_mem reed_solomon ax88796b asix usbnet phy_qcom_usb_hs ipv6 libsha1 >> CPU: 2 UID: 0 PID: 28 Comm: kworker/2:0 Tainted: G W >> 6.18.0-rc1+ #16209 PREEMPT >> Tainted: [W]=WARN >> lr : __qcom_mdt_load+0x210/0x304 [mdt_loader] >> Call trace: >> __pi_memcpy_generic+0x128/0x22c (P) >> qcom_mdt_load+0x68/0x60c [mdt_loader] >> wcnss_load+0x2c/0x5c [qcom_wcnss_pil] >> rproc_start+0x30/0x1b4 >> rproc_boot+0x19c/0x560 >> rproc_auto_boot_callback+0x1c/0x34 >> request_firmware_work_func+0x4c/0x98 >> process_one_work+0x208/0x60c >> worker_thread+0x244/0x388 >> kthread+0x150/0x228 >> ret_from_fork+0x10/0x20 >> Code: 927cec03 cb0e0021 8b0e0042 a9411c26 (a900340c) >> ---[ end trace 0000000000000000 ]--- >> >> >>> --- >>> v7: >>> - Split QCom to separate patch >>> --- >>> drivers/remoteproc/qcom_q6v5_adsp.c | 24 ++++------ >>> drivers/remoteproc/qcom_q6v5_mss.c | 60 ++++++++----------------- >>> drivers/remoteproc/qcom_q6v5_pas.c | 69 +++++++++++------------------ >>> drivers/remoteproc/qcom_q6v5_wcss.c | 25 +++++------ >>> drivers/remoteproc/qcom_wcnss.c | 23 ++++------ >>> 5 files changed, 72 insertions(+), 129 deletions(-) >>> >>> ... >>> diff --git a/drivers/remoteproc/qcom_wcnss.c >>> b/drivers/remoteproc/qcom_wcnss.c >>> index 2c7e519a2254..14005fb049a2 100644 >>> --- a/drivers/remoteproc/qcom_wcnss.c >>> +++ b/drivers/remoteproc/qcom_wcnss.c >>> @@ -526,25 +526,20 @@ static int wcnss_request_irq(struct qcom_wcnss *wcnss, >>> >>> static int wcnss_alloc_memory_region(struct qcom_wcnss *wcnss) >>> { >>> - struct reserved_mem *rmem = NULL; >>> - struct device_node *node; >>> - >>> - node = of_parse_phandle(wcnss->dev->of_node, "memory-region", 0); >>> - if (node) >>> - rmem = of_reserved_mem_lookup(node); >>> - of_node_put(node); >>> + struct resource res; >>> + int ret; >>> >>> - if (!rmem) { >>> + ret = of_reserved_mem_region_to_resource(wcnss->dev->of_node, 0, >>> &res); >>> + if (ret) { >>> dev_err(wcnss->dev, "unable to resolve memory-region\n"); >>> - return -EINVAL; >>> + return ret; >>> } >>> >>> - wcnss->mem_phys = wcnss->mem_reloc = rmem->base; >>> - wcnss->mem_size = rmem->size; >>> - wcnss->mem_region = devm_ioremap_wc(wcnss->dev, wcnss->mem_phys, >>> wcnss->mem_size); >>> + wcnss->mem_phys = wcnss->mem_reloc = res.start; >>> + wcnss->mem_size = resource_size(&res); >>> + wcnss->mem_region = devm_ioremap_resource_wc(wcnss->dev, &res); >> The above line causes the failure. After restoring it to: >> >> wcnss->mem_region = devm_ioremap_wc(wcnss->dev, wcnss->mem_phys, >> wcnss->mem_size); >> >> the mentioned board boots fine again. I'm not sure about other drivers, >> if they also fail the same way as they might not be used on the tested >> board. > Other platforms (non-QCom) were tested also use > devm_ioremap_resource_wc(). So something else is claiming the same > region? Can you dump out /proc/iomem? > > The region is dynamically allocated, so maybe that has something to do with > it.
# dmesg | grep mem OF: reserved mem: 0x000000008e200000..0x000000008e7fffff (6144 KiB) nomap non-reusable wcnss OF: reserved mem: 0x000000008dd00000..0x000000008e1fffff (5120 KiB) nomap non-reusable venus OF: reserved mem: 0x000000008dc00000..0x000000008dcfffff (1024 KiB) nomap non-reusable mba OF: reserved mem: 0x0000000086000000..0x00000000862fffff (3072 KiB) nomap non-reusable tz-apps@86000000 OF: reserved mem: 0x0000000086300000..0x00000000863fffff (1024 KiB) nomap non-reusable smem@86300000 OF: reserved mem: 0x0000000086400000..0x00000000864fffff (1024 KiB) nomap non-reusable hypervisor@86400000 OF: reserved mem: 0x0000000086500000..0x000000008667ffff (1536 KiB) nomap non-reusable tz@86500000 OF: reserved mem: 0x0000000086680000..0x00000000866fffff (512 KiB) nomap non-reusable reserved@86680000 OF: reserved mem: 0x0000000086700000..0x00000000867dffff (896 KiB) nomap non-reusable rmtfs@86700000 OF: reserved mem: 0x00000000867e0000..0x00000000867fffff (128 KiB) nomap non-reusable rfsa@867e0000 OF: reserved mem: 0x0000000086800000..0x00000000892fffff (44032 KiB) nomap non-reusable mpss@86800000 OF: reserved mem: 0x00000000bff00000..0x00000000bfffffff (1024 KiB) map non-reusable ramoops@bff00000 NUMA: Faking a node at [mem 0x0000000080000000-0x00000000bd9fffff] NODE_DATA(0) allocated [mem 0xbd7c6800-0xbd7c943f] DMA [mem 0x0000000080000000-0x00000000bd9fffff] Early memory node ranges node 0: [mem 0x0000000080000000-0x0000000085ffffff] node 0: [mem 0x0000000086000000-0x00000000892fffff] node 0: [mem 0x0000000089300000-0x000000008dbfffff] node 0: [mem 0x000000008dc00000-0x000000008e7fffff] node 0: [mem 0x000000008e800000-0x00000000bd9fffff] ... # cat /proc/iomem ... 80000000-85ffffff : System RAM 80000000-821affff : Kernel code 821b0000-82e5ffff : reserved 82e60000-840fffff : Kernel data 85000000-85013fff : reserved 86000000-892fffff : reserved 89300000-8dbfffff : System RAM 8dc00000-8e7fffff : reserved 8dc00000-8e7fffff : reserved 8e800000-bd9fffff : System RAM b1000000-b6ffffff : reserved b7000000-bbe08fff : reserved bc480000-bd5fffff : reserved bd621000-bd623fff : reserved bd624000-bd724fff : reserved bd725000-bd7b0fff : reserved bd7b2000-bd7b4fff : reserved bd7b5000-bd7b5fff : reserved bd7b6000-bd7c9fff : reserved bd7ca000-bd9fffff : reserved The devm_ioremap_resource_wc() requested region (0x8e200000-0x8e7fffff) is marked as 'reserved' in /proc/iomem. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
