Re: [PATCH v6] usb: dwc3: gadget: Refine the logic for resizing Tx FIFOs

[kernel test robot <lkp@intel.com>]

Hi Akash,

kernel test robot noticed the following build warnings:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus linus/master v6.12-rc3 next-20241016]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Akash-Kumar/usb-dwc3-gadget-Refine-the-logic-for-resizing-Tx-FIFOs/20241016-192104
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20241016111904.11375-1-quic_akakum%40quicinc.com
patch subject: [PATCH v6] usb: dwc3: gadget: Refine the logic for resizing Tx FIFOs
config: i386-buildonly-randconfig-001-20241017 (https://download.01.org/0day-ci/archive/20241017/202410171133.eGVTBDtP-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241017/202410171133.eGVTBDtP-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410171133.eGVTBDtP-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/usb/dwc3/gadget.c: In function 'dwc3_gadget_resize_tx_fifos':
>> drivers/usb/dwc3/gadget.c:777:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     777 |         if (usb_endpoint_xfer_bulk(dep->endpoint.desc) ||
         |         ^~
   drivers/usb/dwc3/gadget.c:782:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
     782 |                 break;
         |                 ^~~~~
   drivers/usb/dwc3/gadget.c:792:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     792 |         if (usb_endpoint_xfer_bulk(dep->endpoint.desc))
         |         ^~
   drivers/usb/dwc3/gadget.c:794:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
     794 |                 break;
         |                 ^~~~~


vim +/if +777 drivers/usb/dwc3/gadget.c

   726	
   727	/*
   728	 * dwc3_gadget_resize_tx_fifos - reallocate fifo spaces for current use-case
   729	 * @dwc: pointer to our context structure
   730	 *
   731	 * This function will a best effort FIFO allocation in order
   732	 * to improve FIFO usage and throughput, while still allowing
   733	 * us to enable as many endpoints as possible.
   734	 *
   735	 * Keep in mind that this operation will be highly dependent
   736	 * on the configured size for RAM1 - which contains TxFifo -,
   737	 * the amount of endpoints enabled on coreConsultant tool, and
   738	 * the width of the Master Bus.
   739	 *
   740	 * In general, FIFO depths are represented with the following equation:
   741	 *
   742	 * fifo_size = mult * ((max_packet + mdwidth)/mdwidth + 1) + 1
   743	 *
   744	 * In conjunction with dwc3_gadget_check_config(), this resizing logic will
   745	 * ensure that all endpoints will have enough internal memory for one max
   746	 * packet per endpoint.
   747	 */
   748	static int dwc3_gadget_resize_tx_fifos(struct dwc3_ep *dep)
   749	{
   750		struct dwc3 *dwc = dep->dwc;
   751		int fifo_0_start;
   752		int ram1_depth;
   753		int fifo_size;
   754		int min_depth;
   755		int num_in_ep;
   756		int remaining;
   757		int num_fifos = 1;
   758		int fifo;
   759		int tmp;
   760	
   761		if (!dwc->do_fifo_resize)
   762			return 0;
   763	
   764		/* resize IN endpoints except ep0 */
   765		if (!usb_endpoint_dir_in(dep->endpoint.desc) || dep->number <= 1)
   766			return 0;
   767	
   768		/* bail if already resized */
   769		if (dep->flags & DWC3_EP_TXFIFO_RESIZED)
   770			return 0;
   771	
   772		ram1_depth = DWC3_RAM1_DEPTH(dwc->hwparams.hwparams7);
   773	
   774		switch (dwc->gadget->speed) {
   775		case USB_SPEED_SUPER_PLUS:
   776		case USB_SPEED_SUPER:
 > 777		if (usb_endpoint_xfer_bulk(dep->endpoint.desc) ||
   778		    usb_endpoint_xfer_isoc(dep->endpoint.desc))
   779			num_fifos = min_t(unsigned int,
   780					  dep->endpoint.maxburst,
   781					  dwc->tx_fifo_resize_max_num);
   782			break;
   783		case USB_SPEED_HIGH:
   784		if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
   785			num_fifos = min_t(unsigned int,
   786					  usb_endpoint_maxp_mult(dep->endpoint.desc) + 1,
   787					  dwc->tx_fifo_resize_max_num);
   788			break;
   789		}
   790			fallthrough;
   791		case USB_SPEED_FULL:
   792		if (usb_endpoint_xfer_bulk(dep->endpoint.desc))
   793			num_fifos = 2;
   794			break;
   795		default:
   796			break;
   797		}
   798	
   799		/* FIFO size for a single buffer */
   800		fifo = dwc3_gadget_calc_tx_fifo_size(dwc, 1);
   801	
   802		/* Calculate the number of remaining EPs w/o any FIFO */
   803		num_in_ep = dwc->max_cfg_eps;
   804		num_in_ep -= dwc->num_ep_resized;
   805	
   806		/* Reserve at least one FIFO for the number of IN EPs */
   807		min_depth = num_in_ep * (fifo + 1);
   808		remaining = ram1_depth - min_depth - dwc->last_fifo_depth;
   809		remaining = max_t(int, 0, remaining);
   810		/*
   811		 * We've already reserved 1 FIFO per EP, so check what we can fit in
   812		 * addition to it.  If there is not enough remaining space, allocate
   813		 * all the remaining space to the EP.
   814		 */
   815		fifo_size = (num_fifos - 1) * fifo;
   816		if (remaining < fifo_size)
   817			fifo_size = remaining;
   818	
   819		fifo_size += fifo;
   820		/* Last increment according to the TX FIFO size equation */
   821		fifo_size++;
   822	
   823		/* Check if TXFIFOs start at non-zero addr */
   824		tmp = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(0));
   825		fifo_0_start = DWC3_GTXFIFOSIZ_TXFSTADDR(tmp);
   826	
   827		fifo_size |= (fifo_0_start + (dwc->last_fifo_depth << 16));
   828		if (DWC3_IP_IS(DWC3))
   829			dwc->last_fifo_depth += DWC3_GTXFIFOSIZ_TXFDEP(fifo_size);
   830		else
   831			dwc->last_fifo_depth += DWC31_GTXFIFOSIZ_TXFDEP(fifo_size);
   832	
   833		/* Check fifo size allocation doesn't exceed available RAM size. */
   834		if (dwc->last_fifo_depth >= ram1_depth) {
   835			dev_err(dwc->dev, "Fifosize(%d) > RAM size(%d) %s depth:%d\n",
   836				dwc->last_fifo_depth, ram1_depth,
   837				dep->endpoint.name, fifo_size);
   838			if (DWC3_IP_IS(DWC3))
   839				fifo_size = DWC3_GTXFIFOSIZ_TXFDEP(fifo_size);
   840			else
   841				fifo_size = DWC31_GTXFIFOSIZ_TXFDEP(fifo_size);
   842	
   843			dwc->last_fifo_depth -= fifo_size;
   844			return -ENOMEM;
   845		}
   846	
   847		dwc3_writel(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1), fifo_size);
   848		dep->flags |= DWC3_EP_TXFIFO_RESIZED;
   849		dwc->num_ep_resized++;
   850	
   851		return 0;
   852	}
   853	

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