Commit a02a26eb authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Greg Kroah-Hartman
Browse files

usb: dwc3: gadget: Ignore Update Transfer cmd params 



The controller doesn't check for Update Transfer command parameters
DEPCMDPAR{0,1,2}. Writing to these registers is unnecessary. Ignoring
this improves performance slightly by removing the register write
delay.

Signed-off-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/997d9ebf38c6bba920d4ee77bd8c77bf81978a55.1638240306.git.Thinh.Nguyen@synopsys.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bc27117c

drivers/usb/dwc3/gadget.c

+11 −3
Original line number Diff line number Diff line
@@ -331,9 +331,17 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd, 
		}

	}



	/*

	 * For some commands such as Update Transfer command, DEPCMDPARn

	 * registers are reserved. Since the driver often sends Update Transfer

	 * command, don't write to DEPCMDPARn to avoid register write delays and

	 * improve performance.

	 */

	if (DWC3_DEPCMD_CMD(cmd) != DWC3_DEPCMD_UPDATETRANSFER) {

		dwc3_writel(dep->regs, DWC3_DEPCMDPAR0, params->param0);

		dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1);

		dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2);

	}



	/*

	 * Synopsys Databook 2.60a states in section 6.3.2.5.6 of that if we're