From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Siddharth Gupta <sidgup@codeaurora.org>
Cc: ohad@wizery.com, linux-remoteproc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, psodagud@codeaurora.org,
stable@vger.kernel.org
Subject: Re: [PATCH 1/3] remoteproc: core: Move cdev add before device add
Date: Thu, 27 May 2021 22:43:32 -0500 [thread overview]
Message-ID: <YLBm5Bd/iwF7Fi+h@builder.lan> (raw)
In-Reply-To: <1621284349-22752-2-git-send-email-sidgup@codeaurora.org>
On Mon 17 May 15:45 CDT 2021, Siddharth Gupta wrote:
> When cdev_add is called after device_add has been called there is no
> way for the userspace to know about the addition of a cdev as cdev_add
> itself doesn't trigger a uevent notification, or for the kernel to
> know about the change to devt. This results in two problems:
> - mknod is never called for the cdev and hence no cdev appears on
> devtmpfs.
> - sysfs links to the new cdev are not established.
>
> The cdev needs to be added and devt assigned before device_add() is
> called in order for the relevant sysfs and devtmpfs entries to be
> created and the uevent to be properly populated.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Regards,
Bjorn
> Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
> ---
> drivers/remoteproc/remoteproc_core.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 626a6b90f..562355a 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -2316,6 +2316,11 @@ int rproc_add(struct rproc *rproc)
> struct device *dev = &rproc->dev;
> int ret;
>
> + /* add char device for this remoteproc */
> + ret = rproc_char_device_add(rproc);
> + if (ret < 0)
> + return ret;
> +
> ret = device_add(dev);
> if (ret < 0)
> return ret;
> @@ -2329,11 +2334,6 @@ int rproc_add(struct rproc *rproc)
> /* create debugfs entries */
> rproc_create_debug_dir(rproc);
>
> - /* add char device for this remoteproc */
> - ret = rproc_char_device_add(rproc);
> - if (ret < 0)
> - return ret;
> -
> /* if rproc is marked always-on, request it to boot */
> if (rproc->auto_boot) {
> ret = rproc_trigger_auto_boot(rproc);
> --
> Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
next prev parent reply other threads:[~2021-05-28 3:43 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 20:45 [PATCH 0/3] remoteproc: core: Fixes for rproc cdev and add Siddharth Gupta
2021-05-17 20:45 ` [PATCH 1/3] remoteproc: core: Move cdev add before device add Siddharth Gupta
2021-05-28 3:43 ` Bjorn Andersson [this message]
2021-05-17 20:45 ` [PATCH 2/3] remoteproc: core: Move validate " Siddharth Gupta
2021-05-28 3:44 ` Bjorn Andersson
2021-05-17 20:45 ` [PATCH 3/3] remoteproc: core: Cleanup device in case of failure Siddharth Gupta
2021-05-28 3:50 ` Bjorn Andersson
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