[PATCH] usb: core: add urb->sgt parameter description

[PATCH] usb: core: add urb->sgt parameter description

[Xu Yang]

The parameter description of urb->sgt is lost, this will add it for
completeness.

Reported-by: Stephen Rothwell<sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20250711182803.1d548467@canb.auug.org.au/
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
---
 include/linux/usb.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 535ac37198a1..9d662c6abb4d 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1455,6 +1455,10 @@ typedef void (*usb_complete_t)(struct urb *);
  * @sg: scatter gather buffer list, the buffer size of each element in
  * 	the list (except the last) must be divisible by the endpoint's
  * 	max packet size if no_sg_constraint isn't set in 'struct usb_bus'
+ * @sgt: used to hold a scatter gather table returned by usb_alloc_noncoherent(),
+ *      which describes the allocated non-coherent and possibly non-contiguous
+ *      memory and is guaranteed to have 1 single DMA mapped segment. The
+ *      allocated memory needs to be freed by usb_free_noncoherent().
  * @num_mapped_sgs: (internal) number of mapped sg entries
  * @num_sgs: number of entries in the sg list
  * @transfer_buffer_length: How big is transfer_buffer.  The transfer may
-- 
2.34.1

Re: [PATCH] usb: core: add urb->sgt parameter description

[Greg KH]

On Mon, Jul 21, 2025 at 06:44:17PM +0800, Xu Yang wrote:
> The parameter description of urb->sgt is lost, this will add it for
> completeness.
> 
> Reported-by: Stephen Rothwell<sfr@canb.auug.org.au>
> Closes: https://lore.kernel.org/all/20250711182803.1d548467@canb.auug.org.au/
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> ---
>  include/linux/usb.h | 4 ++++
>  1 file changed, 4 insertions(+)

What commit id does this fix?

thanks,

greg k-h

Re: [PATCH] usb: core: add urb->sgt parameter description

[Stephen Rothwell]

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Hi Greg,

On Mon, 21 Jul 2025 13:04:09 +0200 Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jul 21, 2025 at 06:44:17PM +0800, Xu Yang wrote:
> > The parameter description of urb->sgt is lost, this will add it for
> > completeness.
> > 
> > Reported-by: Stephen Rothwell<sfr@canb.auug.org.au>
> > Closes: https://lore.kernel.org/all/20250711182803.1d548467@canb.auug.org.au/
> > Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> > ---
> >  include/linux/usb.h | 4 ++++
> >  1 file changed, 4 insertions(+)  
> 
> What commit id does this fix?

Fixes: 488e6eaab88c ("usb: core: add dma-noncoherent buffer alloc and free API")

from the usb tree.

-- 
Cheers,
Stephen Rothwell

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Re: [PATCH] usb: core: add urb->sgt parameter description

[Randy Dunlap]

On 7/21/25 3:44 AM, Xu Yang wrote:
> The parameter description of urb->sgt is lost, this will add it for
> completeness.
> 
> Reported-by: Stephen Rothwell<sfr@canb.auug.org.au>
> Closes: https://lore.kernel.org/all/20250711182803.1d548467@canb.auug.org.au/
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>

Thanks.

> ---
>  include/linux/usb.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index 535ac37198a1..9d662c6abb4d 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -1455,6 +1455,10 @@ typedef void (*usb_complete_t)(struct urb *);
>   * @sg: scatter gather buffer list, the buffer size of each element in
>   * 	the list (except the last) must be divisible by the endpoint's
>   * 	max packet size if no_sg_constraint isn't set in 'struct usb_bus'
> + * @sgt: used to hold a scatter gather table returned by usb_alloc_noncoherent(),
> + *      which describes the allocated non-coherent and possibly non-contiguous
> + *      memory and is guaranteed to have 1 single DMA mapped segment. The
> + *      allocated memory needs to be freed by usb_free_noncoherent().
>   * @num_mapped_sgs: (internal) number of mapped sg entries
>   * @num_sgs: number of entries in the sg list
>   * @transfer_buffer_length: How big is transfer_buffer.  The transfer may

-- 
~Randy