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

[cang@codeaurora.org]

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.