diff options
| author |   Thinh Nguyen <Thinh.Nguyen@synopsys.com> | 2021-11-29 18:53:16 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-03 12:02:49 +0100 |
| commit | a02a26eb0aeaa2859a8b2f182bd5b5f7228ee1fe (patch) | |
| tree | 505225ed08843e596cb8faff4eb0104a785194ee /drivers/usb/dwc3/gadget.c | |
| parent | usb: dwc3: gadget: Skip checking Update Transfer status (diff) | |
| download | linux-dev-a02a26eb0aeaa2859a8b2f182bd5b5f7228ee1fe.tar.xz linux-dev-a02a26eb0aeaa2859a8b2f182bd5b5f7228ee1fe.zip | |
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: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/997d9ebf38c6bba920d4ee77bd8c77bf81978a55.1638240306.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 00b3f19c4d3e..f66baaef8a40 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -331,9 +331,17 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd, } } - dwc3_writel(dep->regs, DWC3_DEPCMDPAR0, params->param0); - dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1); - dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2); + /* + * 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 |