Re: [PATCH] firmware: zynqmp: fix loading for PMU FWv1.1

[Michael Tretter <m.tretter@pengutronix.de>]

On Fri, 23 Jun 2023 13:42:56 +0200, Steffen Trumtrar wrote:
> FPGA programming on ZynqMP is done by the PMU. The SoC just hands a
> file to the PMU and lets it load this file to the FPGA.
> 
> The bitstream that is sent to the FPGA consists of two headers, the
> optional struct bs_header and a binary-header. See comment in driver:
> 
>  (...)
>  * Bitstream can be provided with an optinal header (`struct bs_header`).
>  * The true bitstream starts with the binary-header composed of 21 words:
>  (...)
> 
> The PMUFW v1.0 had a feature for taking the bitstream only, skipping
> the header, or including the binary-header and only skipping the
> optional header. This is controlled via the BIT_ONLY_BIN flag. When
> the flag is set, the complete header should be skipped.
> 
> The current implementation sets the flag *and* sends the binary-header
> to the PMU:
> 
> 	header_length = get_header_length(mgr->buf, mgr->size);
> 	(...)
> 	body = (u32 *)&mgr->buf[header_length];
> 
> get_header_length searches for the first DUMMY_WORD, i.e. the beginning
> of the binary header. Then we set body to this offset, skipping the
> optional header.
> 
> The flag is always set to ZYNQMP_FPGA_BIT_ONLY_BIN, which is then obviously
> incorrect. It seems like the PMUFW v1.0 was capable of still handling this
> although the flag was set.
> 
> The newer PMUFW v1.1 doesn't support this and expects the flag to be
> unset and getting handed binary-header+bitstream. This is the same as
> the linux kernel handles bitstream loading on the ZynqMP. There the flag
> is also always unset.
> 
> As this wasn't correct in the first place (although it most likely still
> worked depending on PMUFW and its configuration), we won't break anything
> when we just set the flag to zero as the PMUFW v1.1 expects it.
> 
> TLDR: set fpga_load flags to zero to fix firmwareloading with newer
> PMUFW versions.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>

Reviewed-by: Michael Tretter <m.tretter@pengutronix.de>

> ---
>  drivers/firmware/zynqmp-fpga.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/zynqmp-fpga.c b/drivers/firmware/zynqmp-fpga.c
> index 9c160e9098..1a9a5c1b2c 100644
> --- a/drivers/firmware/zynqmp-fpga.c
> +++ b/drivers/firmware/zynqmp-fpga.c
> @@ -206,7 +206,7 @@ static int fpgamgr_program_finish(struct firmware_handler *fh)
>  	enum xilinx_byte_order byte_order;
>  	dma_addr_t addr;
>  	int status = 0;
> -	u8 flags = ZYNQMP_FPGA_BIT_ONLY_BIN;
> +	u8 flags = 0;
>  
>  	if (!mgr->buf) {
>  		status = -ENOBUFS;
> -- 
> 2.41.0
> 
>