Messages in this thread | | | Date | Thu, 22 Jun 2023 14:48:36 -0500 | Subject | Re: [PATCH v2 3/4] spi: Split transfers larger than max size | From | Eddie James <> |
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On 9/27/22 06:21, Vincent Whitchurch wrote: > A couple of drivers call spi_split_transfers_maxsize() from their > ->prepare_message() callbacks to split transfers which are too big for > them to handle. Add support in the core to do this based on > ->max_transfer_size() to avoid code duplication.
Hello,
I've been testing AT25 functionality in linux 6.1 and I believe this patch is breaking the AT25 protocol. It will split a write command up such that some of the data is in a different transfer than the write enable and address. According to my understanding of the AT25 spec, that doesn't work... Someone correct me if I'm wrong though. Do we need a flag to enable/disable this behavior depending on the client perhaps?
Thanks,
Eddie
> > Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> > --- > drivers/spi/spi.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index f41a8c2752b8..44e4352d948b 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -1649,6 +1649,15 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, > > trace_spi_message_start(msg); > > + ret = spi_split_transfers_maxsize(ctlr, msg, > + spi_max_transfer_size(msg->spi), > + GFP_KERNEL | GFP_DMA); > + if (ret) { > + msg->status = ret; > + spi_finalize_current_message(ctlr); > + return ret; > + } > + > if (ctlr->prepare_message) { > ret = ctlr->prepare_message(ctlr, msg); > if (ret) {
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