Re: [PATCH v2 6/7] misc: bcm-vk: add Broadcom VK driver

[Scott Branden]

Hi Randy,

On 2020-02-19 5:04 p.m., Randy Dunlap wrote:
> Hi,
>
> On 2/19/20 4:48 PM, Scott Branden wrote:
> > diff --git a/drivers/misc/bcm-vk/Kconfig b/drivers/misc/bcm-vk/Kconfig
> > new file mode 100644
> > index 000000000000..c75dfb89a38d
> > --- /dev/null
> > +++ b/drivers/misc/bcm-vk/Kconfig
> > @@ -0,0 +1,42 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +#
> > +# Broadcom VK device
> > +#
> > +config BCM_VK
> > +	tristate "Support for Broadcom VK Accelerators"
> > +	depends on PCI_MSI
> > +	default m
> Need to justify default m. Normally we don't add drivers as enabled unless
> they are required for basic (boot) operation.
Will remove default m as not needed to boot. Interesting other offload 
engines misc/ocxl/Kconfig and misc/cxl/Kconfig have default m.
> > +	help
> > +	  Select this option to enable support for Broadcom
> > +	  VK Accelerators.  VK is used for performing
> > +	  specific video offload processing.  This driver enables
> > +	  userspace programs to access these accelerators via /dev/bcm-vk.N
> > +	  devices.
> > +
> > +	  If unsure, say N.
> > +
> > +if BCM_VK
> > +
> > +config BCM_VK_H2VK_VERIFY_AND_RETRY
> > +	bool "Host To VK Verifiy Data and Retry"
> 	                 Verify
>
> > +	help
> > +	  Turn on to verify the data passed down to VK is good,
> > +	  and if not, do a retry until it succeeds.
> No timeout on that retry?
This is only enabled for debug purposes or fpga workarounds - no need 
for a timeout.
> > +	  This is a debug/workaround on FPGA PCIe timing issues
> > +	  but may be found useful for debugging other PCIe hardware issues.
> > +	  Small performance loss by enabling this debug config.
> > +	  For properly operating PCIe hardware no need to enable this.
> > +
> > +	  If unsure, say N.
> > +
> > +config BCM_VK_QSTATS
> > +	bool "VK Queue Statistics"
> > +	help
> > +	  Turn on to enable Queue Statistics.
> > +	  These are useful for debugging purposes.
> > +	  Some performance loss by enabling this debug config.
> > +	  For properly operating PCIe hardware no need to enable this.
> > +
> > +	  If unsure, say N.
> > +
> > +endif
> cheers.