[PATCH 0/2] usb: xhci: dbc: 2 smalll fixes for 'xhci_dbc_alloc_requests()'

[PATCH 0/2] usb: xhci: dbc: 2 smalll fixes for 'xhci_dbc_alloc_requests()'

[Christophe JAILLET]

Christophe JAILLET (2):
  usb: xhci: dbc: Simplify error handling in 'xhci_dbc_alloc_requests()'
  usb: xhci: dbc: Use GFP_KERNEL instead of GFP_ATOMIC in
    'xhci_dbc_alloc_requests()'

 drivers/usb/host/xhci-dbgtty.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.20.1

[PATCH 1/2] usb: xhci: dbc: Simplify error handling in 'xhci_dbc_alloc_requests()'

[Christophe JAILLET]

If the 'kmalloc()' fails, we need to undo the previous
'dbc_alloc_request()' call.

Because of the more similar function name, it is more logical to use
'dbc_free_request()' instead of 'xhci_dbc_free_req()'.

Both are equivalent here because:
 static void xhci_dbc_free_req(struct dbc_ep *dep, struct dbc_request *req)
 {
 	kfree(req->buf);
 	dbc_free_request(dep, req);
 }
and 'req->buf' is known to be NULL at this point

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/usb/host/xhci-dbgtty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index aff79ff5aba4..845939f8a0b8 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -146,7 +146,7 @@ xhci_dbc_alloc_requests(struct dbc_ep *dep, struct list_head *head,
 		req->length = DBC_MAX_PACKET;
 		req->buf = kmalloc(req->length, GFP_KERNEL);
 		if (!req->buf) {
-			xhci_dbc_free_req(dep, req);
+			dbc_free_request(dep, req);
 			break;
 		}
 
-- 
2.20.1

[PATCH 2/2] usb: xhci: dbc: Use GFP_KERNEL instead of GFP_ATOMIC in 'xhci_dbc_alloc_requests()'

[Christophe JAILLET]

There is no need to use GFP_ATOMIC to allocate 'req'. GFP_KERNEL should be
enough and is already used for another allocation juste a few lines below.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
I've done my best to check if a spinlock can be hold when reaching this
code. Apparently it is never the case.
But double check to be sure that it is not the kmalloc that should use
GFP_ATOMIC.
---
 drivers/usb/host/xhci-dbgtty.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index 845939f8a0b8..be726c791323 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -139,7 +139,7 @@ xhci_dbc_alloc_requests(struct dbc_ep *dep, struct list_head *head,
 	struct dbc_request	*req;
 
 	for (i = 0; i < DBC_QUEUE_SIZE; i++) {
-		req = dbc_alloc_request(dep, GFP_ATOMIC);
+		req = dbc_alloc_request(dep, GFP_KERNEL);
 		if (!req)
 			break;
 
-- 
2.20.1

Re: [PATCH 0/2] usb: xhci: dbc: 2 smalll fixes for 'xhci_dbc_alloc_requests()'

[Mathias Nyman]

On 31.7.2019 15.51, Christophe JAILLET wrote:
> 
> 
> Christophe JAILLET (2):
>    usb: xhci: dbc: Simplify error handling in 'xhci_dbc_alloc_requests()'
>    usb: xhci: dbc: Use GFP_KERNEL instead of GFP_ATOMIC in
>      'xhci_dbc_alloc_requests()'
> 
>   drivers/usb/host/xhci-dbgtty.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 

Thanks, adding to queue

-Mathias