2014-09-25 21:32 GMT+09:00 Dolev Raviv <draviv@xxxxxxxxxxxxxx>:
> +static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
> +{
> + int ret = 0;
> +
> + hba->sdev_ufs_device = __scsi_add_device(hba->host, 0, 0,
> + ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN), NULL);
> + if (IS_ERR(hba->sdev_ufs_device)) {
> + ret = PTR_ERR(hba->sdev_ufs_device);
> + hba->sdev_ufs_device = NULL;
> + goto out;
> + }
> +
> + hba->sdev_boot = __scsi_add_device(hba->host, 0, 0,
> + ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_BOOT_WLUN), NULL);
> + if (IS_ERR(hba->sdev_boot)) {
> + ret = PTR_ERR(hba->sdev_boot);
> + hba->sdev_boot = NULL;
> + goto remove_sdev_ufs_device;
> + }
> +
> + hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
> + ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
These __scsi_add_device() calls for W-LUs increase the module reference
count of ufshcd.ko by three. But no one calls scsi_device_put() for
these W-LUs, so it is impossible to unload ufshcd.ko.
There are scsi_remove_device() calls for W-LUs in ufshcd_scsi_remove_wlus(),
But these calls do nothing (please see a comment below).
I could fix this issue by putting scsi_device_put() just after each
__scsi_add_device() call. I'll prepare a patch if I haven't missed
something.
> + if (IS_ERR(hba->sdev_rpmb)) {
> + ret = PTR_ERR(hba->sdev_rpmb);
> + hba->sdev_rpmb = NULL;
> + goto remove_sdev_boot;
> + }
> + goto out;
> +
> +remove_sdev_boot:
> + scsi_remove_device(hba->sdev_boot);
> +remove_sdev_ufs_device:
> + scsi_remove_device(hba->sdev_ufs_device);
> +out:
> + return ret;
> +}
> +
> +/**
> + * ufshcd_scsi_remove_wlus - Removes the W-LUs which were added by
> + * ufshcd_scsi_add_wlus()
> + * @hba: per-adapter instance
> + *
> + */
> +static void ufshcd_scsi_remove_wlus(struct ufs_hba *hba)
> +{
> + if (hba->sdev_ufs_device) {
> + scsi_remove_device(hba->sdev_ufs_device);
> + hba->sdev_ufs_device = NULL;
> + }
> +
> + if (hba->sdev_boot) {
> + scsi_remove_device(hba->sdev_boot);
> + hba->sdev_boot = NULL;
> + }
> +
> + if (hba->sdev_rpmb) {
> + scsi_remove_device(hba->sdev_rpmb);
> + hba->sdev_rpmb = NULL;
> + }
> +}
When ufshcd_scsi_remove_wlus() is called in ufshcd_remove(), these
three W-LU devices have already been deleted by scsi_remove_host() which
is called just before ufshcd_scsi_remove_wlus(). The scsi
device state of these W-LU devices is SDEV_DEL at this time, and
scsi_remove_device() does nothing.
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