* Re: [PATCH] usb: dwc3: gadget: Fix logical condition
2019-11-13 6:15 [PATCH] usb: dwc3: gadget: Fix logical condition Tejas Joglekar
@ 2019-11-22 4:00 ` Tejas Joglekar
2019-12-02 11:30 ` Tejas Joglekar
2019-12-03 13:58 ` Felipe Balbi
2020-01-31 3:25 ` Jack Pham
2 siblings, 1 reply; 6+ messages in thread
From: Tejas Joglekar @ 2019-11-22 4:00 UTC (permalink / raw)
To: Felipe Balbi, linux-usb; +Cc: John Youn, Thinh Nguyen, stable, greg
Hello Balbi,
This is a critical patch fix for dwc3, can you please review ?
On 11/13/2019 11:45 AM, Tejas Joglekar wrote:
> This patch corrects the condition to kick the transfer without
> giving back the requests when either request has remaining data
> or when there are pending SGs. The && check was introduced during
> spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
>
> Fixes: f38e35dd84e2 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
> ---
> drivers/usb/dwc3/gadget.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 86dc1db788a9..e07159e06f9a 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2485,7 +2485,7 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
>
> req->request.actual = req->request.length - req->remaining;
>
> - if (!dwc3_gadget_ep_request_completed(req) &&
> + if (!dwc3_gadget_ep_request_completed(req) ||
> req->num_pending_sgs) {
> __dwc3_gadget_kick_transfer(dep);
> goto out;
Thanks & Regards,
Tejas Joglekar
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] usb: dwc3: gadget: Fix logical condition
2019-11-22 4:00 ` Tejas Joglekar
@ 2019-12-02 11:30 ` Tejas Joglekar
0 siblings, 0 replies; 6+ messages in thread
From: Tejas Joglekar @ 2019-12-02 11:30 UTC (permalink / raw)
To: Felipe Balbi, linux-usb
Cc: Tejas Joglekar, John Youn, Thinh Nguyen, stable, greg
Hello,
Gentle reminder...
On 11/22/2019 9:30 AM, Tejas Joglekar wrote:
> Hello Balbi,
> This is a critical patch fix for dwc3, can you please review ?
>
> On 11/13/2019 11:45 AM, Tejas Joglekar wrote:
>> This patch corrects the condition to kick the transfer without
>> giving back the requests when either request has remaining data
>> or when there are pending SGs. The && check was introduced during
>> spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
>>
>> Fixes: f38e35dd84e2 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>> ---
>> drivers/usb/dwc3/gadget.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 86dc1db788a9..e07159e06f9a 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -2485,7 +2485,7 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
>>
>> req->request.actual = req->request.length - req->remaining;
>>
>> - if (!dwc3_gadget_ep_request_completed(req) &&
>> + if (!dwc3_gadget_ep_request_completed(req) ||
>> req->num_pending_sgs) {
>> __dwc3_gadget_kick_transfer(dep);
>> goto out;
> Thanks & Regards,
>
> Tejas Joglekar
>
Thanks,
Tejas Joglekar
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: dwc3: gadget: Fix logical condition
2019-11-13 6:15 [PATCH] usb: dwc3: gadget: Fix logical condition Tejas Joglekar
2019-11-22 4:00 ` Tejas Joglekar
@ 2019-12-03 13:58 ` Felipe Balbi
2020-01-31 3:25 ` Jack Pham
2 siblings, 0 replies; 6+ messages in thread
From: Felipe Balbi @ 2019-12-03 13:58 UTC (permalink / raw)
To: Tejas Joglekar, linux-usb; +Cc: John Youn, Tejas Joglekar, Thinh Nguyen, stable
[-- Attachment #1: Type: text/plain, Size: 605 bytes --]
Hi,
Tejas Joglekar <Tejas.Joglekar@synopsys.com> writes:
> This patch corrects the condition to kick the transfer without
> giving back the requests when either request has remaining data
> or when there are pending SGs. The && check was introduced during
> spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
>
> Fixes: f38e35dd84e2 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
Indeed this is a very important fix :-)
I'll queue it up.
--
balbi
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] usb: dwc3: gadget: Fix logical condition
2019-11-13 6:15 [PATCH] usb: dwc3: gadget: Fix logical condition Tejas Joglekar
2019-11-22 4:00 ` Tejas Joglekar
2019-12-03 13:58 ` Felipe Balbi
@ 2020-01-31 3:25 ` Jack Pham
2020-01-31 8:07 ` Felipe Balbi
2 siblings, 1 reply; 6+ messages in thread
From: Jack Pham @ 2020-01-31 3:25 UTC (permalink / raw)
To: Tejas Joglekar; +Cc: Felipe Balbi, linux-usb, John Youn, Thinh Nguyen, stable
Hi Tejas & Felipe,
On Wed, Nov 13, 2019 at 11:45:16AM +0530, Tejas Joglekar wrote:
> This patch corrects the condition to kick the transfer without
> giving back the requests when either request has remaining data
> or when there are pending SGs. The && check was introduced during
> spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
>
> Fixes: f38e35dd84e2 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
> ---
> drivers/usb/dwc3/gadget.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 86dc1db788a9..e07159e06f9a 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2485,7 +2485,7 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
>
> req->request.actual = req->request.length - req->remaining;
>
> - if (!dwc3_gadget_ep_request_completed(req) &&
> + if (!dwc3_gadget_ep_request_completed(req) ||
> req->num_pending_sgs) {
> __dwc3_gadget_kick_transfer(dep);
> goto out;
Been staring at this for a while--I think I see a potential issue but
not sure if it is or not.
If this condition is true and causes an early return, the 'ret' value
could be 0 which could allow the caller in cleanup_completed_requests()
to continue looping over the started_list and calling
cleanup_completed_request() again on the next req. But we just issued
another START or UPDATE transfer command on the previous incomplete req
and now the loop continued to try to reclaim the next TRB (and increment
the dequeue pointer and whatnot) when it might actually be in progress.
According to the code before f38e35dd84e2,
list_for_each_entry_safe(req, tmp, &dep->started_list, list) {
...
if (!dwc3_gadget_ep_request_completed(req) ||
req->num_pending_sgs) {
__dwc3_gadget_kick_transfer(dep);
break;
}
The 'goto out' used to be a 'break', which terminates the list loop. But
with the refactored code, the loop can only terminate if 'ret' is
non-zero.
I haven't seen any real issue with the code as-is yet, but was just
wondering if the 'goto out' should be replaced with a return 1?
Jack
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] usb: dwc3: gadget: Fix logical condition
2020-01-31 3:25 ` Jack Pham
@ 2020-01-31 8:07 ` Felipe Balbi
0 siblings, 0 replies; 6+ messages in thread
From: Felipe Balbi @ 2020-01-31 8:07 UTC (permalink / raw)
To: Jack Pham, Tejas Joglekar; +Cc: linux-usb, John Youn, Thinh Nguyen, stable
[-- Attachment #1: Type: text/plain, Size: 2601 bytes --]
Hi,
Jack Pham <jackp@codeaurora.org> writes:
> Hi Tejas & Felipe,
>
> On Wed, Nov 13, 2019 at 11:45:16AM +0530, Tejas Joglekar wrote:
>> This patch corrects the condition to kick the transfer without
>> giving back the requests when either request has remaining data
>> or when there are pending SGs. The && check was introduced during
>> spliting up the dwc3_gadget_ep_cleanup_completed_requests() function.
>>
>> Fixes: f38e35dd84e2 ("usb: dwc3: gadget: split dwc3_gadget_ep_cleanup_completed_requests()")
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>> ---
>> drivers/usb/dwc3/gadget.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 86dc1db788a9..e07159e06f9a 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -2485,7 +2485,7 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
>>
>> req->request.actual = req->request.length - req->remaining;
>>
>> - if (!dwc3_gadget_ep_request_completed(req) &&
>> + if (!dwc3_gadget_ep_request_completed(req) ||
>> req->num_pending_sgs) {
>> __dwc3_gadget_kick_transfer(dep);
>> goto out;
>
> Been staring at this for a while--I think I see a potential issue but
> not sure if it is or not.
>
> If this condition is true and causes an early return, the 'ret' value
> could be 0 which could allow the caller in cleanup_completed_requests()
> to continue looping over the started_list and calling
> cleanup_completed_request() again on the next req. But we just issued
> another START or UPDATE transfer command on the previous incomplete req
> and now the loop continued to try to reclaim the next TRB (and increment
> the dequeue pointer and whatnot) when it might actually be in progress.
>
> According to the code before f38e35dd84e2,
>
> list_for_each_entry_safe(req, tmp, &dep->started_list, list) {
>
> ...
> if (!dwc3_gadget_ep_request_completed(req) ||
> req->num_pending_sgs) {
> __dwc3_gadget_kick_transfer(dep);
> break;
> }
>
> The 'goto out' used to be a 'break', which terminates the list loop. But
> with the refactored code, the loop can only terminate if 'ret' is
> non-zero.
ret is initialized properly by dwc3_gadget_ep_reclaim*(). That goto is
correct.
> I haven't seen any real issue with the code as-is yet, but was just
> wondering if the 'goto out' should be replaced with a return 1?
let us know if you find any problems
--
balbi
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread