Re: [PATCH 1/2] scsi: ufs: Put SCSI host after remove it

cang
2019-12-16T14:31:39Z

On 2019-12-15 02:32, Bart Van Assche wrote:
> On 12/14/19 8:03 AM, Can Guo wrote:
>> In ufshcd_remove(), after SCSI host is removed, put it once so that
>> its
>> resources can be released.
>>
>> Signed-off-by: Can Guo <cang@codeaurora.org>
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index b5966fa..a86b0fd 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -8251,6 +8251,7 @@ void ufshcd_remove(struct ufs_hba *hba)
>> ufs_bsg_remove(hba);
>> ufs_sysfs_remove_nodes(hba->dev);
>> scsi_remove_host(hba->host);
>> + scsi_host_put(hba->host);
>> /* disable interrupts */
>> ufshcd_disable_intr(hba, hba->intr_mask);
>> ufshcd_hba_stop(hba, true);
>
> Hi Can,
>
> The UFS driver may queue work asynchronously and that asynchronous
> work may refer to the SCSI host, e.g. ufshcd_err_handler(). Is it
> guaranteed that all that asynchronous work has finished before
> scsi_host_put() is called?
>
> Thanks,
>
> Bart.

Hi Bart,

As SCSI host is allocated in ufshcd_platform_init() during platform
drive probe, it is much more appropriate if platform driver calls
ufshcd_dealloc_host() in their own drv->remove() path. How do you
think if I change it as below? If it is OK to you, please ignore my
previous mails.

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 3d4582e..ea45756 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -3239,6 +3239,7 @@ static int ufs_qcom_remove(struct platform_device
*pdev)

pm_runtime_get_sync(&(pdev)->dev);
ufshcd_remove(hba);
+ ufshcd_dealloc_host(hba);
return 0;
}

Thanks,

Can Guo.