From: Eddie James <eajames@linux.ibm.com> To: Vincent Whitchurch <vincent.whitchurch@axis.com>, broonie@kernel.org, krzysztof.kozlowski@linaro.org, andi@etezian.org Cc: kernel@axis.com, alim.akhtar@samsung.com, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 3/4] spi: Split transfers larger than max size Date: Thu, 22 Jun 2023 14:48:36 -0500 [thread overview] Message-ID: <6dff003d-c727-e4a3-b5d3-f58beb2b02cb@linux.ibm.com> (raw) In-Reply-To: <20220927112117.77599-4-vincent.whitchurch@axis.com> 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) {
WARNING: multiple messages have this Message-ID (diff)
From: Eddie James <eajames@linux.ibm.com> To: Vincent Whitchurch <vincent.whitchurch@axis.com>, broonie@kernel.org, krzysztof.kozlowski@linaro.org, andi@etezian.org Cc: kernel@axis.com, alim.akhtar@samsung.com, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 3/4] spi: Split transfers larger than max size Date: Thu, 22 Jun 2023 14:48:36 -0500 [thread overview] Message-ID: <6dff003d-c727-e4a3-b5d3-f58beb2b02cb@linux.ibm.com> (raw) In-Reply-To: <20220927112117.77599-4-vincent.whitchurch@axis.com> 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) { _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-06-22 19:49 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-27 11:21 [PATCH v2 0/4] spi: Fix DMA bugs in (not only) spi-s3c64xx Vincent Whitchurch 2022-09-27 11:21 ` Vincent Whitchurch 2022-09-27 11:21 ` [PATCH v2 1/4] spi: Save current RX and TX DMA devices Vincent Whitchurch 2022-09-27 11:21 ` Vincent Whitchurch 2022-09-27 11:21 ` [PATCH v2 2/4] spi: Fix cache corruption due to DMA/PIO overlap Vincent Whitchurch 2022-09-27 11:21 ` Vincent Whitchurch 2022-09-30 11:20 ` Marek Szyprowski 2022-09-30 11:20 ` Marek Szyprowski 2022-09-30 12:10 ` Robin Murphy 2022-09-30 12:10 ` Robin Murphy 2022-10-03 11:29 ` Vincent Whitchurch 2022-10-03 11:29 ` Vincent Whitchurch 2022-09-27 11:21 ` [PATCH v2 3/4] spi: Split transfers larger than max size Vincent Whitchurch 2022-09-27 11:21 ` Vincent Whitchurch 2023-06-22 19:48 ` Eddie James [this message] 2023-06-22 19:48 ` Eddie James 2023-06-22 21:16 ` Mark Brown 2023-06-22 21:16 ` Mark Brown 2023-06-23 16:45 ` Eddie James 2023-06-23 16:45 ` Eddie James 2023-06-23 17:16 ` Mark Brown 2023-06-23 17:16 ` Mark Brown 2022-09-27 11:21 ` [PATCH v2 4/4] spi: s3c64xx: Fix large transfers with DMA Vincent Whitchurch 2022-09-27 11:21 ` Vincent Whitchurch 2022-09-28 17:27 ` [PATCH v2 0/4] spi: Fix DMA bugs in (not only) spi-s3c64xx Mark Brown 2022-09-28 17:27 ` Mark Brown
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