* [PATCH] usb: core: Remove unnecessary memset()
@ 2018-12-04 14:31 Suwan Kim
2018-12-10 20:06 ` Alan Stern
0 siblings, 1 reply; 2+ messages in thread
From: Suwan Kim @ 2018-12-04 14:31 UTC (permalink / raw)
To: gregkh
Cc: stern, linux-usb, mathias.nyman, heikki.krogerus, linux-kernel, balbi
register_root_hub() calls memset() setting usb_dev->bus->devmap.
devicemap to 0 during hcd probe function (usb_hcd_pci_probe). But
in previous function which is also the procedure of usb_hcd_pci_probe(),
usb_bus_init() already initialized bus->devmap calling memset().
Furthermore, register_root_hub() is called only once in kernel.
So, calling memset() which resets usb_bus->devmap.devicemap in
register_root_hub() is redundant.
Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
---
drivers/usb/core/hcd.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 487025d31d44..015b126ce455 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1074,8 +1074,6 @@ static int register_root_hub(struct usb_hcd *hcd)
usb_dev->devnum = devnum;
usb_dev->bus->devnum_next = devnum + 1;
- memset (&usb_dev->bus->devmap.devicemap, 0,
- sizeof usb_dev->bus->devmap.devicemap);
set_bit (devnum, usb_dev->bus->devmap.devicemap);
usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
--
2.19.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] usb: core: Remove unnecessary memset()
2018-12-04 14:31 [PATCH] usb: core: Remove unnecessary memset() Suwan Kim
@ 2018-12-10 20:06 ` Alan Stern
0 siblings, 0 replies; 2+ messages in thread
From: Alan Stern @ 2018-12-10 20:06 UTC (permalink / raw)
To: Suwan Kim
Cc: gregkh, linux-usb, mathias.nyman, heikki.krogerus, linux-kernel, balbi
On Tue, 4 Dec 2018, Suwan Kim wrote:
> register_root_hub() calls memset() setting usb_dev->bus->devmap.
> devicemap to 0 during hcd probe function (usb_hcd_pci_probe). But
> in previous function which is also the procedure of usb_hcd_pci_probe(),
> usb_bus_init() already initialized bus->devmap calling memset().
> Furthermore, register_root_hub() is called only once in kernel.
> So, calling memset() which resets usb_bus->devmap.devicemap in
> register_root_hub() is redundant.
>
> Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
> ---
> drivers/usb/core/hcd.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 487025d31d44..015b126ce455 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -1074,8 +1074,6 @@ static int register_root_hub(struct usb_hcd *hcd)
>
> usb_dev->devnum = devnum;
> usb_dev->bus->devnum_next = devnum + 1;
> - memset (&usb_dev->bus->devmap.devicemap, 0,
> - sizeof usb_dev->bus->devmap.devicemap);
> set_bit (devnum, usb_dev->bus->devmap.devicemap);
> usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
Acked-by: Alan Stern <stern@rowland.harvard.edu>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-12-04 14:31 [PATCH] usb: core: Remove unnecessary memset() Suwan Kim
2018-12-10 20:06 ` Alan Stern
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