On 2019-12-11 19:22, Avri Altman wrote:
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@xxxxxxxxxxxxxx>
>
> 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.
Looks like we needed to manage the ufs-bsg nodes using an IDA, instead
of host_no?
Marking one ufs-bsg dev with host_no still has its advantage. If we have
more
than one hba host, we can find the right ufs-bsgX dev by reading the
sg/sd/bsg
device's host->host_unique_id (through SCSI_IOCTL_GET_IDLUN for
example).
But If ufs-bsg has its own ID, we will lost this "mapping".
Thanks,
Can Guo.
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
