Re: [PATCH 4/9] USB: Convert from tasklet to BH workqueue

From: Greg KH <gregkh@linuxfoundation.org>
To: Allen Pais <apais@linux.microsoft.com>
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Subject: Re: [PATCH 4/9] USB: Convert from tasklet to BH workqueue
Date: Wed, 27 Mar 2024 17:55:31 +0100	[thread overview]
Message-ID: <2024032753-probable-blatancy-80bf@gregkh> (raw)
In-Reply-To: <20240327160314.9982-5-apais@linux.microsoft.com>

On Wed, Mar 27, 2024 at 04:03:09PM +0000, Allen Pais wrote:
> The only generic interface to execute asynchronously in the BH context is
> tasklet; however, it's marked deprecated and has some design flaws. To
> replace tasklets, BH workqueue support was recently added. A BH workqueue
> behaves similarly to regular workqueues except that the queued work items
> are executed in the BH context.
> 
> This patch converts drivers/infiniband/* from tasklet to BH workqueue.

No it does not, I think your changelog is wrong :(

> 
> Based on the work done by Tejun Heo <tj@kernel.org>
> Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-6.10
> 
> Signed-off-by: Allen Pais <allen.lkml@gmail.com>
> ---
>  drivers/usb/atm/usbatm.c            | 55 +++++++++++++++--------------
>  drivers/usb/atm/usbatm.h            |  3 +-
>  drivers/usb/core/hcd.c              | 22 ++++++------
>  drivers/usb/gadget/udc/fsl_qe_udc.c | 21 +++++------
>  drivers/usb/gadget/udc/fsl_qe_udc.h |  4 +--
>  drivers/usb/host/ehci-sched.c       |  2 +-
>  drivers/usb/host/fhci-hcd.c         |  3 +-
>  drivers/usb/host/fhci-sched.c       | 10 +++---
>  drivers/usb/host/fhci.h             |  5 +--
>  drivers/usb/host/xhci-dbgcap.h      |  3 +-
>  drivers/usb/host/xhci-dbgtty.c      | 15 ++++----
>  include/linux/usb/cdc_ncm.h         |  2 +-
>  include/linux/usb/usbnet.h          |  2 +-
>  13 files changed, 76 insertions(+), 71 deletions(-)
> 
> diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
> index 2da6615fbb6f..74849f24e52e 100644
> --- a/drivers/usb/atm/usbatm.c
> +++ b/drivers/usb/atm/usbatm.c
> @@ -17,7 +17,7 @@
>   *  		- Removed the limit on the number of devices
>   *  		- Module now autoloads on device plugin
>   *  		- Merged relevant parts of sarlib
> - *  		- Replaced the kernel thread with a tasklet
> + *  		- Replaced the kernel thread with a work

a "work"?

>   *  		- New packet transmission code
>   *  		- Changed proc file contents
>   *  		- Fixed all known SMP races
> @@ -68,6 +68,7 @@
>  #include <linux/wait.h>
>  #include <linux/kthread.h>
>  #include <linux/ratelimit.h>
> +#include <linux/workqueue.h>
>  
>  #ifdef VERBOSE_DEBUG
>  static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len);
> @@ -249,7 +250,7 @@ static void usbatm_complete(struct urb *urb)
>  	/* vdbg("%s: urb 0x%p, status %d, actual_length %d",
>  	     __func__, urb, status, urb->actual_length); */
>  
> -	/* Can be invoked from task context, protect against interrupts */
> +	/* Can be invoked from work context, protect against interrupts */

"workqueue"?  This too seems wrong.

Same for other comment changes in this patch.

thanks,

greg k-h