Re: [PATCH v2 1/3] scsi: ufs: Put SCSI host after remove it

cang
2019-12-11T11:06:55Z

On 2019-12-11 18:37, Avri Altman 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>
>
> This is not really part of this patchset, is it?
>

Hi Avri,

I put this change in the same patchset due to
#1. The main patch has dependency on it
#2. Consider a scenario where platform driver is also compiled as a
module, say ufs_qcom.ko.
In this case, we have two modules, ufs-qcom.ko and ufs-bsg.ko. If do
insmod ufs-qcom.ko
then rmmod ufs-qcom.ko and do insmod ufs-qcom.ko again, without this
change, because scsi
host was not release, the new scsi host will have a different host
number, meaning
hba->host->host_no will be 1, but not 0. Now if do insmod ufs-bsg.ko
now, the ufs-bsg dev
created in /dev/bsg/ will be ufs-bsg1, but not ufs-bsg0. If keep
trying these operations,
the ufs-bsg device's name will be messed up. This change make sure
after ufs-qcom.ko is removed
and installed back, its hba->host->host_no stays 0, so that ufs-bsg
device name stays same.

Thanks,

Can Guo.

>> ---
>> drivers/scsi/ufs/ufshcd.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> 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);
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
>> Forum,
>> a Linux Foundation Collaborative Project