Re: [PATCH 1/4] fpga mgr: Introduce FPGA capabilities

atull
2016-11-14T14:07:22Z

[-- Attachment #1: Type: text/plain, Size: 2357 bytes --]

On Mon, 7 Nov 2016, Moritz Fischer wrote:

> Add FPGA capabilities as a way to express the capabilities
> of a given FPGA manager.
>
> Removes code duplication by comparing the low-level driver's
> capabilities at the framework level rather than having each driver
> check for supported operations in the write_init() callback.
>
> This allows for extending with additional capabilities, similar
> to the the dmaengine framework's implementation.
>
> Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
> Cc: Alan Tull <atull@opensource.altera.com>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> ---
>
> Changes from RFC:
> * in the RFC the caps weren't actually stored into the struct fpga_mgr
>
> Note:
>
> If people disagree on the typedef being a 'false positive' I can fix
> that in a future rev of the patchset.
>
> Thanks,
>
> Moritz
>
> ---
> drivers/fpga/fpga-mgr.c | 15 ++++++++++++++
> drivers/fpga/socfpga.c | 10 +++++-----
> drivers/fpga/zynq-fpga.c | 7 ++++++-
> include/linux/fpga/fpga-mgr.h | 46 ++++++++++++++++++++++++++++++++++++++++++-
> 4 files changed, 71 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index 953dc91..ed57c17 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -49,6 +49,18 @@ int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, const char *buf,
> struct device *dev = &mgr->dev;
> int ret;
>
> + if (flags & FPGA_MGR_PARTIAL_RECONFIG &&
> + !fpga_mgr_has_cap(FPGA_MGR_CAP_PARTIAL_RECONF, mgr->caps)) {
> + dev_err(dev, "Partial reconfiguration not supported\n");
> + return -ENOTSUPP;
> + }
> +
> + if (flags & FPGA_MGR_FULL_RECONFIG &&
> + !fpga_mgr_has_cap(FPGA_MGR_CAP_FULL_RECONF, mgr->caps)) {
> + dev_err(dev, "Full reconfiguration not supported\n");
> + return -ENOTSUPP;
> + }
> +

Could you move the checks to their own function like
'fpga_mgr_check_caps()' or something? I really like it if we can keep
the functions short, like a screen or so where it's practicle to do
so and I could see the number of caps growing here. The only
counter argument I could think of is if a cap affects the sequence
in this function. Hmmm...

Alan