[PATCH v10 1/2] net: brcm: netXtreme driver

[Roman Bacik]

Hi Marek,

> -----Original Message-----
> From: Marek Behún <kabel at kernel.org>
> Sent: Monday, November 8, 2021 3:43 PM
> To: Roman Bacik <roman.bacik at broadcom.com>
> Cc: U-Boot Mailing List <u-boot at lists.denx.de>; Pali Rohar
> <pali at kernel.org>; Bharat Gooty <bharat.gooty at broadcom.com>; Joe
> Hershberger <joe.hershberger at ni.com>; Ramon Fried
> <rfried.dev at gmail.com>
> Subject: Re: [PATCH v10 1/2] net: brcm: netXtreme driver
>
> Hello Roman,
>
> some last requests from me.
>
> On Mon,  8 Nov 2021 14:46:10 -0800
> Roman Bacik <roman.bacik at broadcom.com> wrote:
>
> > +#define bnxt_down_chip(bp)     bnxt_hwrm_run(down_chip, bp, 0)
> > +#define bnxt_bring_chip(bp)    bnxt_hwrm_run(bring_chip, bp, 1)
>
> Could these be changed to functions instead of macros, please?

Ok, we will make the change.

>
> > +int bnxt_free_rx_iob(struct bnxt *bp)
> > +{
> > +	unsigned int i;
> > +
> > +	if (!(FLAG_TEST(bp->flag_hwrm, VALID_RX_IOB)))
> > +		return STATUS_SUCCESS;
>
> Please change all STATUS_SUCCESS to 0 and STATUS_FAILURE to either -1
> or appropriate -errno, as is customary in U-Boot.

This status is returned from our HW/FW so it would make more sense to keep
it as is.
But we will change it per your request and we will replace STATUS_SUCCESS
with 0 and STATUS_FAILURE with -1 and hence loose status codes actually
returned by HW/FW.

>
> At first I thought that you have implemented this driver by starting
> from kernel's implementation. They look very similar. But it was
> probably an old version of kernel implementation (perhaps broadcom
> internal?), because many things are different now.
>
> > +static void set_rx_desc(u8 *buf, void *iob, u16 cons_id, u32 iob_idx)
> > +{
> > +	struct rx_prod_pkt_bd *desc;
> > +	u16 off = cons_id * sizeof(struct rx_prod_pkt_bd);
> > +
> > +	desc = (struct rx_prod_pkt_bd *)&buf[off];
> > +	desc->flags_type = RX_PROD_PKT_BD_TYPE_RX_PROD_PKT;
> > +	desc->len	 = MAX_ETHERNET_PACKET_BUFFER_SIZE;
>
> What bugs me with this driver most is that it reimplements many things
on
> its own. MAX_ETHERNET_PACKET_BUFFER_SIZE is 1536, but we have
> PKTSIZE_ALIGN in include/net.h for that.
>
> > +	bp->link_status       = STATUS_LINK_DOWN;
>
> This can be a simple bool: link is either up or down...

The bp structure is passed to our HW/FW, which expects a valid integer
link_status. We cannot make this change and have the driver working.

>
>
> > +typedef int (*hwrm_func_t)(struct bnxt *bp);
> > +
> > +hwrm_func_t down_chip[] = {
> > +	bnxt_hwrm_cfa_l2_filter_free,    /* Free l2 filter  */
> > +	bnxt_free_rx_iob,                /* Free rx iob     */
> > +	bnxt_hwrm_vnic_free,             /* Free vnic       */
> > +	bnxt_hwrm_ring_free_grp,         /* Free ring group */
> > +	bnxt_hwrm_ring_free_rx,          /* Free rx ring    */
> > +	bnxt_hwrm_ring_free_tx,          /* Free tx ring    */
> > +	bnxt_hwrm_ring_free_cq,          /* Free CQ ring    */
> > +	bnxt_hwrm_stat_ctx_free,         /* Free Stat ctx   */
> > +	bnxt_hwrm_func_drv_unrgtr,       /* unreg driver    */
> > +	NULL,
> > +};
> > +
> > +hwrm_func_t bring_chip[] = {
> > +	bnxt_hwrm_ver_get,              /* HWRM_VER_GET                 */
> > +	bnxt_hwrm_func_reset_req,       /* HWRM_FUNC_RESET              */
> > +	bnxt_hwrm_func_drv_rgtr,        /* HWRM_FUNC_DRV_RGTR           */
> > +	bnxt_hwrm_func_resource_qcaps,  /*
> HWRM_FUNC_RESOURCE_QCAPS     */
> > +	bnxt_hwrm_func_qcfg_req,        /* HWRM_FUNC_QCFG               */
> > +	bnxt_hwrm_func_qcaps_req,       /* HWRM_FUNC_QCAPS              */
> > +	bnxt_hwrm_get_link_speed,       /* HWRM_NVM_GET_VARIABLE -
> 203  */
> > +	bnxt_hwrm_port_mac_cfg,         /* HWRM_PORT_MAC_CFG            */
> > +	bnxt_qphy_link,                 /* HWRM_PORT_PHY_QCFG           */
> > +	bnxt_hwrm_func_cfg_req,         /* HWRM_FUNC_CFG - ring
> resource*/
> > +	bnxt_hwrm_stat_ctx_alloc,       /* Allocate Stat Ctx ID         */
> > +	bnxt_hwrm_ring_alloc_cq,        /* Allocate CQ Ring             */
> > +	bnxt_hwrm_ring_alloc_tx,        /* Allocate Tx ring             */
> > +	bnxt_hwrm_ring_alloc_rx,        /* Allocate Rx Ring             */
> > +	bnxt_hwrm_ring_alloc_grp,       /* Create Ring Group            */
> > +	post_rx_buffers,                /* Post RX buffers              */
> > +	bnxt_hwrm_set_async_event,      /* ENABLES_ASYNC_EVENT_CR
> */
> > +	bnxt_hwrm_vnic_alloc,           /* Alloc VNIC                   */
> > +	bnxt_hwrm_vnic_cfg,             /* Config VNIC                  */
> > +	bnxt_hwrm_cfa_l2_filter_alloc,  /* Alloc L2 Filter              */
> > +	get_phy_link,                   /* Get Physical Link            */
> > +	NULL,
> > +};
> > +
> > +int bnxt_hwrm_run(hwrm_func_t cmds[], struct bnxt *bp, int flag)
> > +{
> > +	hwrm_func_t *ptr;
> > +	int ret;
> > +	int status = STATUS_SUCCESS;
> > +
> > +	for (ptr = cmds; *ptr; ++ptr) {
> > +		ret = (*ptr)(bp);
> > +		if (ret) {
> > +			status = STATUS_FAILURE;
> > +			/* Continue till all cleanup routines are called
*/
> > +			if (flag)
> > +				return STATUS_FAILURE;
>
> Please change this function to return 0 on success and the error value
> from last failed function on failure:
>   int ret = 0;
>   for (...) {
>     ret = (*ptr)(bp);
>     if (ret)
>       break;
>   }
>   return ret;
>
> If you can, maybe return -errno codes that make sense on failures in
> places where you now return STATUS_FAILURE.
>

We will change the method as requested. Note the status code is coming
from HW/FW so returning it to uboot upper layers would not make much
sense. But we will change STATUS_SUCCESS and STATUS_FAILURE to 0 and -1 as
requested.

>
> I'll be honest that I don't like how this driver uses code construct
> that are many time different from that in U-Boot/Linux. I guess this
> is how the Broadcom people wrote it, and it probably looked this way
> also in Linux, but was changed since then to conform to Linux style. (Or
> maybe they didn't accept it until it conformed?)
>
> Anyway, these are probably the last changes that I will be suggesting.
> I don't like many things here, but I guess beggars cannot be choosers,
> and we in U-Boot are more on the side of beggars when talking about
> man-hours companies are willing to spend for U-Boot :( Since the
> driver works for you, maybe we should accept it as it is.
>
> Marek

To be honest changing status codes coming from FW does not seem right. But
we will try to make the requested changes.
Thanks,

Roman

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