Messages in this thread | | | Date | Wed, 11 Dec 2019 11:44:08 +0000 | From | cang@codeauro ... | Subject | Re: [PATCH v2 1/3] scsi: ufs: Put SCSI host after remove it |
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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@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. > 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
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