On Thu, Nov 27, 2025 at 8:28 AM Marek Szyprowski <[email protected]> wrote: > > Hi Rob, > > 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. Rob
