Messages in this thread Patch in this message |  | | Date | Sun, 15 Dec 2019 06:24:43 +0800 | From | cang@codeauro ... | Subject | Re: [PATCH 1/2] scsi: ufs: Put SCSI host after remove it |
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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,
Thanks for pointing it out. I noticed that you are changing this path too in below 2 changes. https://marc.info/?l=linux-scsi&m=157591520015924&w=2 https://marc.info/?l=linux-scsi&m=157591519915923&w=2
Actually the async works you pointed may also affect your change, because you may tear down the hba->cmd_queue too early, as there can be devm commands sent by clock gating, eeh_work and eh_work after that point, meaning when blk_get_request is called in exec_dev_cmd(), hba->cmd_queue may have been released already.
@@ -8263,6 +8232,7 @@ void ufshcd_remove(struct ufs_hba *hba) { ufs_bsg_remove(hba); ufs_sysfs_remove_nodes(hba->dev); + blk_cleanup_queue(hba->cmd_queue); scsi_remove_host(hba->host); /* disable interrupts */ ufshcd_disable_intr(hba, hba->intr_mask);
How do you think if I replace my patch with below one? In this way, you can also move blk_cleanup_queue() behind cancel_work_sync(eh_work).
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index b5966fa..bd4ae75 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8251,15 +8251,17 @@ void ufshcd_remove(struct ufs_hba *hba) ufs_bsg_remove(hba); ufs_sysfs_remove_nodes(hba->dev); scsi_remove_host(hba->host); - /* disable interrupts */ - ufshcd_disable_intr(hba, hba->intr_mask); - ufshcd_hba_stop(hba, true); - ufshcd_exit_clk_scaling(hba); ufshcd_exit_clk_gating(hba); if (ufshcd_is_clkscaling_supported(hba)) device_remove_file(hba->dev, &hba->clk_scaling.enable_attr); + cancel_work_sync(&hba->eeh_work); + cancel_work_sync(&hba->eh_work); + /* disable interrupts */ + ufshcd_disable_intr(hba, hba->intr_mask); + ufshcd_hba_stop(hba, true); ufshcd_hba_exit(hba); + ufshcd_dealloc_host(hba); } EXPORT_SYMBOL_GPL(ufshcd_remove);
-- Thanks,
Can Guo.
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