Re: [PATCH] [SCSI] wd719x: Avoid calling request_firmware under spinlock

From: John Garry
Date: Thu Sep 15 2016 - 10:10:06 EST


On 15/09/2016 14:48, Vaishali Thakkar wrote:
It is preferrable to use request_firmware where sleeping is
allowed. Using it under spinlock can cause blocking. Here,
the function wd719x_chip_init calls request_firmware while
holding a spinlock. So, let's access it outside the spinlock.

Coccinelle is used to detect the issue.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@xxxxxxxxxx>
---
Please note that the patch is compile-tested only. And this change
may require driver testing.
---
drivers/scsi/wd719x.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/wd719x.c b/drivers/scsi/wd719x.c
index e3da1a2..b8e57f3 100644
--- a/drivers/scsi/wd719x.c
+++ b/drivers/scsi/wd719x.c
@@ -518,13 +518,14 @@ static int wd719x_host_reset(struct scsi_cmnd *cmd)
int result;

dev_info(&wd->pdev->dev, "host reset requested\n");
- spin_lock_irqsave(wd->sh->host_lock, flags);
+

In the version of code I have flags is only used for this spinlock, so can flags be removed?

/* Try to reinit the RISC */
if (wd719x_chip_init(wd) == 0)
result = SUCCESS;
else
result = FAILED;

+ spin_lock_irqsave(wd->sh->host_lock, flags);
/* flush all SCBs */
list_for_each_entry_safe(scb, tmp, &wd->active_scbs, list) {
struct scsi_cmnd *tmp_cmd = scb->cmd;