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Commit 3f658cde authored by Alexey Orishko's avatar Alexey Orishko Committed by David S. Miller
Browse files

cdc_ncm: fix MTU and max_datagram_size handling 



Changes/fixes:
- inform device if max_datagram_size was changed by host
- max_datagram_size can't be bigger MTU in ETH func descr
- fix constants definitions to enable running CAIF service over NCM

Tested on Intel/ARM.

Reviewed-by: default avatarSjur Brændeland <sjur.brandeland@stericsson.com>
Tested-by: default avatarDmitry Tarnyagin <Dmitry.Tarnyagin@stericsson.com>
Signed-off-by: default avatarAlexey Orishko <alexey.orishko@stericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c84ff1d6

drivers/net/usb/cdc_ncm.c

+16 −18
Original line number Diff line number Diff line
@@ -58,8 +58,8 @@ 
#define USB_CDC_NCM_NDP16_LENGTH_MIN		0x10



/* Maximum NTB length */

#define	CDC_NCM_NTB_MAX_SIZE_TX			16384	/* bytes */

#define	CDC_NCM_NTB_MAX_SIZE_RX			16384	/* bytes */

#define	CDC_NCM_NTB_MAX_SIZE_TX			32768	/* bytes */

#define	CDC_NCM_NTB_MAX_SIZE_RX			32768	/* bytes */



/* Minimum value for MaxDatagramSize, ch. 6.2.9 */

#define	CDC_NCM_MIN_DATAGRAM_SIZE		1514	/* bytes */
@@ -67,13 +67,13 @@ 
#define	CDC_NCM_MIN_TX_PKT			512	/* bytes */



/* Default value for MaxDatagramSize */

#define	CDC_NCM_MAX_DATAGRAM_SIZE		2048	/* bytes */

#define	CDC_NCM_MAX_DATAGRAM_SIZE		8192	/* bytes */



/*

 * Maximum amount of datagrams in NCM Datagram Pointer Table, not counting

 * the last NULL entry. Any additional datagrams in NTB would be discarded.

 */

#define	CDC_NCM_DPT_DATAGRAMS_MAX		32

#define	CDC_NCM_DPT_DATAGRAMS_MAX		40



/* Maximum amount of IN datagrams in NTB */

#define	CDC_NCM_DPT_DATAGRAMS_IN_MAX		0 /* unlimited */
@@ -366,26 +366,24 @@ static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx) 
		if (err < 0) {

			pr_debug("GET_MAX_DATAGRAM_SIZE failed, use size=%u\n",

						CDC_NCM_MIN_DATAGRAM_SIZE);

			kfree(max_datagram_size);

		} else {

			ctx->max_datagram_size =

				le16_to_cpu(*max_datagram_size);

			/* Check Eth descriptor value */

			if (eth_max_sz < CDC_NCM_MAX_DATAGRAM_SIZE) {

			if (ctx->max_datagram_size > eth_max_sz)

					ctx->max_datagram_size = eth_max_sz;

			} else {

				if (ctx->max_datagram_size >

						CDC_NCM_MAX_DATAGRAM_SIZE)



			if (ctx->max_datagram_size > CDC_NCM_MAX_DATAGRAM_SIZE)

				ctx->max_datagram_size =

						CDC_NCM_MAX_DATAGRAM_SIZE;

			}



			if (ctx->max_datagram_size < CDC_NCM_MIN_DATAGRAM_SIZE)

				ctx->max_datagram_size =

					CDC_NCM_MIN_DATAGRAM_SIZE;



			/* if value changed, update device */

			if (ctx->max_datagram_size !=

					le16_to_cpu(*max_datagram_size)) {

				err = usb_control_msg(ctx->udev,

						usb_sndctrlpipe(ctx->udev, 0),

						USB_CDC_SET_MAX_DATAGRAM_SIZE,
@@ -394,14 +392,14 @@ static u8 cdc_ncm_setup(struct cdc_ncm_ctx *ctx) 
						0,

						iface_no, max_datagram_size,

						2, 1000);

			kfree(max_datagram_size);

max_dgram_err:

				if (err < 0)

				pr_debug("SET_MAX_DATAGRAM_SIZE failed\n");

					pr_debug("SET_MAX_DGRAM_SIZE failed\n");

			}



		}

		kfree(max_datagram_size);

	}



max_dgram_err:

	if (ctx->netdev->mtu != (ctx->max_datagram_size - ETH_HLEN))

		ctx->netdev->mtu = ctx->max_datagram_size - ETH_HLEN;