[v5,1/8] usb: gadget: f_ecm/f_eem/f_rndis: Setup quirk_avoids_skb_reserve

Message ID 4c7b3a3b23b44f4115de1745c65d719a3f70c4db.1502280695.git.digetx@gmail.com
State Superseded
Headers show

Commit Message

Dmitry Osipenko Aug. 9, 2017, 12:19 p.m.
This quirk is required to make USB Ethernet gadget working with HW that
can't cope with unaligned DMA. For some reason only f_ncm handles that
quirk, let's handle it in the rest of the network models. All models have
been tested with a ChipIdea UDC driver on NVIDIA Tegra20 SoC that require
DMA to be aligned.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/usb/gadget/function/f_ecm.c   | 7 +++++++
 drivers/usb/gadget/function/f_eem.c   | 5 +++++
 drivers/usb/gadget/function/f_rndis.c | 4 ++++
 3 files changed, 16 insertions(+)

Comments

Felipe Balbi Aug. 15, 2017, 9:49 a.m. | #1
Hi,

Dmitry Osipenko <digetx@gmail.com> writes:
> This quirk is required to make USB Ethernet gadget working with HW that
> can't cope with unaligned DMA. For some reason only f_ncm handles that
> quirk, let's handle it in the rest of the network models. All models have
> been tested with a ChipIdea UDC driver on NVIDIA Tegra20 SoC that require
> DMA to be aligned.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/usb/gadget/function/f_ecm.c   | 7 +++++++
>  drivers/usb/gadget/function/f_eem.c   | 5 +++++
>  drivers/usb/gadget/function/f_rndis.c | 4 ++++
>  3 files changed, 16 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
> index 4c488d15b6f6..1d198055fd74 100644
> --- a/drivers/usb/gadget/function/f_ecm.c
> +++ b/drivers/usb/gadget/function/f_ecm.c
> @@ -584,6 +584,13 @@ static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
>  			 */
>  			ecm->port.is_zlp_ok =
>  				gadget_is_zlp_supported(cdev->gadget);
> +
> +			/* Setup DMA alignment workaround for UDC's that
> +			 * need it.
> +			 */
> +			ecm->port.no_skb_reserve =
> +				gadget_avoids_skb_reserve(cdev->gadget);

looks like the quirk should be moved to u_ether.c instead.
Dmitry Osipenko Aug. 15, 2017, 3:45 p.m. | #2
Hi,

On 15.08.2017 12:49, Felipe Balbi wrote:
> Dmitry Osipenko <digetx@gmail.com> writes:
>> This quirk is required to make USB Ethernet gadget working with HW that
>> can't cope with unaligned DMA. For some reason only f_ncm handles that
>> quirk, let's handle it in the rest of the network models. All models have
>> been tested with a ChipIdea UDC driver on NVIDIA Tegra20 SoC that require
>> DMA to be aligned.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  drivers/usb/gadget/function/f_ecm.c   | 7 +++++++
>>  drivers/usb/gadget/function/f_eem.c   | 5 +++++
>>  drivers/usb/gadget/function/f_rndis.c | 4 ++++
>>  3 files changed, 16 insertions(+)
>>
>> diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
>> index 4c488d15b6f6..1d198055fd74 100644
>> --- a/drivers/usb/gadget/function/f_ecm.c
>> +++ b/drivers/usb/gadget/function/f_ecm.c
>> @@ -584,6 +584,13 @@ static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
>>  			 */
>>  			ecm->port.is_zlp_ok =
>>  				gadget_is_zlp_supported(cdev->gadget);
>> +
>> +			/* Setup DMA alignment workaround for UDC's that
>> +			 * need it.
>> +			 */
>> +			ecm->port.no_skb_reserve =
>> +				gadget_avoids_skb_reserve(cdev->gadget);
> 
> looks like the quirk should be moved to u_ether.c instead.
> 

Indeed, thank you very much for the suggestion. I'll prepare a new revision of
the patch.

Patch

diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
index 4c488d15b6f6..1d198055fd74 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -584,6 +584,13 @@  static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 			 */
 			ecm->port.is_zlp_ok =
 				gadget_is_zlp_supported(cdev->gadget);
+
+			/* Setup DMA alignment workaround for UDC's that
+			 * need it.
+			 */
+			ecm->port.no_skb_reserve =
+				gadget_avoids_skb_reserve(cdev->gadget);
+
 			ecm->port.cdc_filter = DEFAULT_FILTER;
 			DBG(cdev, "activate ecm\n");
 			net = gether_connect(&ecm->port);
diff --git a/drivers/usb/gadget/function/f_eem.c b/drivers/usb/gadget/function/f_eem.c
index 007ec6e4a5d4..74e2453d8ac5 100644
--- a/drivers/usb/gadget/function/f_eem.c
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -215,6 +215,11 @@  static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		 */
 		eem->port.is_zlp_ok = 1;
 		eem->port.cdc_filter = DEFAULT_FILTER;
+
+		/* setup DMA alignment workaround for UDC's that*need it */
+		eem->port.no_skb_reserve =
+				gadget_avoids_skb_reserve(cdev->gadget);
+
 		DBG(cdev, "activate eem\n");
 		net = gether_connect(&eem->port);
 		if (IS_ERR(net))
diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
index 16562e461121..1b379c051a84 100644
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -593,6 +593,10 @@  static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		 */
 		rndis->port.cdc_filter = 0;
 
+		/* Setup DMA alignment workaround for UDC's that need it */
+		rndis->port.no_skb_reserve =
+				gadget_avoids_skb_reserve(cdev->gadget);
+
 		DBG(cdev, "RNDIS RX/TX early activation ... \n");
 		net = gether_connect(&rndis->port);
 		if (IS_ERR(net))