On 26-08-2026 18:55, Vinayak Katoch wrote: > of_platform_populate() only guarantees that child devices are registered, > not that their probes have completed before it returns. This creates a > window where fastrpc_cb_init() may not have run for all context bank > nodes, leaving the channel context partially initialised. > > Iterate over the child device tree nodes directly, initialising each > qcom,fastrpc-compute-cb device synchronously. This ensures all context > banks are fully initialised before fastrpc_rpmsg_probe() returns. Since > fastrpc_cb_driver is no longer needed as an independent platform driver, > remove it along with its match table and remove callback. Set > OF_POPULATED_BUS on the rpmsg node so that of_platform_depopulate() > correctly removes the manually created CB devices on teardown. > > Signed-off-by: Vinayak Katoch <[email protected]> > --- > drivers/misc/fastrpc.c | 83 > ++++++++++++++++++-------------------------------- > 1 file changed, 29 insertions(+), 54 deletions(-) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index d4fac2caca86..a153107d0085 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -2363,7 +2363,7 @@ static const struct file_operations fastrpc_fops = { > .compat_ioctl = fastrpc_device_ioctl, > }; > > -static int fastrpc_cb_probe(struct platform_device *pdev) > +static int fastrpc_cb_init(struct platform_device *pdev) > { > struct fastrpc_channel_ctx *cctx; > struct fastrpc_session_ctx *sess; > @@ -2385,7 +2385,7 @@ static int fastrpc_cb_probe(struct platform_device > *pdev) > spin_lock_irqsave(&cctx->lock, flags); > if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) { > spin_unlock_irqrestore(&cctx->lock, flags); > - dev_err(&pdev->dev, "too many sessions\n"); > + dev_err(dev, "too many sessions\n"); > return -ENOSPC; > } > dma_bits = cctx->soc_data->dma_addr_bits_default; > @@ -2419,38 +2419,6 @@ static int fastrpc_cb_probe(struct platform_device > *pdev) > return 0; > } > > -static void fastrpc_cb_remove(struct platform_device *pdev) > -{ > - struct fastrpc_channel_ctx *cctx = dev_get_drvdata(pdev->dev.parent); > - struct fastrpc_session_ctx *sess = dev_get_drvdata(&pdev->dev); > - unsigned long flags; > - int i; > - > - spin_lock_irqsave(&cctx->lock, flags); > - for (i = 0; i < FASTRPC_MAX_SESSIONS; i++) { > - if (cctx->session[i].sid == sess->sid) { > - cctx->session[i].valid = false; > - cctx->sesscount--; > - } > - } > - spin_unlock_irqrestore(&cctx->lock, flags); > -} > - > -static const struct of_device_id fastrpc_match_table[] = { > - { .compatible = "qcom,fastrpc-compute-cb" }, > - { } > -}; > - > -static struct platform_driver fastrpc_cb_driver = { > - .probe = fastrpc_cb_probe, > - .remove = fastrpc_cb_remove, > - .driver = { > - .name = "qcom,fastrpc-cb", > - .of_match_table = fastrpc_match_table, > - .suppress_bind_attrs = true, > - }, > -}; > - > static int fastrpc_device_register(struct device *dev, struct > fastrpc_channel_ctx *cctx, > bool is_secured, const char *domain) > { > @@ -2642,12 +2610,29 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device > *rpdev) > data->rpdev = rpdev; > dev_set_drvdata(&rpdev->dev, data); > > - err = of_platform_populate(rdev->of_node, NULL, NULL, rdev); > - if (err) > - goto err_deregister_fdev; > + of_node_set_flag(rdev->of_node, OF_POPULATED_BUS); > + > + for_each_available_child_of_node_scoped(rdev->of_node, np) { > + struct platform_device *pdev; > + > + if (!of_device_is_compatible(np, "qcom,fastrpc-compute-cb")) > + continue; > + > + pdev = of_platform_device_create(np, NULL, rdev); > + if (!pdev) { > + err = -EINVAL; > + goto err_depopulate; > + } > + > + err = fastrpc_cb_init(pdev); > + if (err) > + goto err_depopulate; > + } > > return 0; > > +err_depopulate: > + of_platform_depopulate(rdev); > err_deregister_fdev: > if (data->fdevice) > misc_deregister(&data->fdevice->miscdev); > @@ -2677,6 +2662,7 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device > *rpdev) > struct fastrpc_buf *buf, *b; > struct fastrpc_user *user; > unsigned long flags; > + int i; > > /* No invocations past this point */ > spin_lock_irqsave(&cctx->lock, flags); > @@ -2697,6 +2683,11 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device > *rpdev) > if (cctx->remote_heap) > fastrpc_buf_free(cctx->remote_heap); > > + spin_lock_irqsave(&cctx->lock, flags); > + for (i = 0; i < FASTRPC_MAX_SESSIONS; i++) > + cctx->session[i].valid = false; > + spin_unlock_irqrestore(&cctx->lock, flags); > + > of_platform_depopulate(&rpdev->dev); should this also be removed?> > fastrpc_channel_ctx_put(cctx); > @@ -2786,28 +2777,12 @@ static struct rpmsg_driver fastrpc_driver = { > > static int fastrpc_init(void) > { > - int ret; > - > - ret = platform_driver_register(&fastrpc_cb_driver); > - if (ret < 0) { > - pr_err("fastrpc: failed to register cb driver\n"); > - return ret; > - } > - > - ret = register_rpmsg_driver(&fastrpc_driver); > - if (ret < 0) { > - pr_err("fastrpc: failed to register rpmsg driver\n"); > - platform_driver_unregister(&fastrpc_cb_driver); > - return ret; > - } > - > - return 0; > + return register_rpmsg_driver(&fastrpc_driver); > } > module_init(fastrpc_init); can you use module_rpmsg_driver() instead?> > static void fastrpc_exit(void) > { > - platform_driver_unregister(&fastrpc_cb_driver); > unregister_rpmsg_driver(&fastrpc_driver); > } > module_exit(fastrpc_exit); >
