Hi Arnd,
Thank you for the patch.
On Mon, Nov 15, 2021 at 09:54:00AM +0100, Arnd Bergmann wrote:
From: Arnd Bergmann arnd@arndb.de
The display driver wants to pass a custom flag to the DMA engine driver, which it started doing by using the slave_id field that was traditionally used for a different purpose.
As there is no longer a correct use for the slave_id field, it should really be removed, and the remaining users changed over to something different.
The new mechanism for passing nonstandard settings is using the .peripheral_config field, so use that to pass a newly defined structure here, making it clear that this will not work in portable drivers.
Signed-off-by: Arnd Bergmann arnd@arndb.de
drivers/dma/xilinx/xilinx_dpdma.c | 12 ++++++++---- drivers/gpu/drm/xlnx/zynqmp_disp.c | 9 +++++++-- include/linux/dma/xilinx_dpdma.h | 11 +++++++++++ 3 files changed, 26 insertions(+), 6 deletions(-) create mode 100644 include/linux/dma/xilinx_dpdma.h
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c index ce5c66e6897d..e2c1ef7a659c 100644 --- a/drivers/dma/xilinx/xilinx_dpdma.c +++ b/drivers/dma/xilinx/xilinx_dpdma.c @@ -12,6 +12,7 @@ #include <linux/clk.h> #include <linux/debugfs.h> #include <linux/delay.h> +#include <linux/dma/xilinx_dpdma.h> #include <linux/dmaengine.h> #include <linux/dmapool.h> #include <linux/interrupt.h> @@ -1273,6 +1274,7 @@ static int xilinx_dpdma_config(struct dma_chan *dchan, struct dma_slave_config *config) { struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
struct xilinx_dpdma_peripheral_config *pconfig; unsigned long flags;
/*
@@ -1285,11 +1287,13 @@ static int xilinx_dpdma_config(struct dma_chan *dchan, spin_lock_irqsave(&chan->lock, flags);
/*
* Abuse the slave_id to indicate that the channel is part of a video* group.
* Abuse the peripheral_config to indicate that the channel is part
Is it still an abuse, or is this now the right way to pass custom data to the DMA engine driver ?
* of a video group.
- if (chan->id <= ZYNQMP_DPDMA_VIDEO2)
chan->video_group = config->slave_id != 0;
- pconfig = config->peripheral_config;
This could be moved to the variable declaration above, up to you.
- if (chan->id <= ZYNQMP_DPDMA_VIDEO2 &&
config->peripheral_size == sizeof(*pconfig))
Silently ignoring a size mismatch isn't nice. Could we validate the size at the beginning of the function and return an error ?
With these issues addressed,
Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com
chan->video_group = pconfig->video_group;spin_unlock_irqrestore(&chan->lock, flags);
diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c index ff2b308d8651..11c409cbc88e 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c @@ -24,6 +24,7 @@
#include <linux/clk.h> #include <linux/delay.h> +#include <linux/dma/xilinx_dpdma.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/module.h> @@ -1058,14 +1059,18 @@ static void zynqmp_disp_layer_set_format(struct zynqmp_disp_layer *layer, zynqmp_disp_avbuf_set_format(layer->disp, layer, layer->disp_fmt);
/*
* Set slave_id for each DMA channel to indicate they're part of a
* Set pconfig for each DMA channel to indicate they're part of a*/ for (i = 0; i < info->num_planes; i++) { struct zynqmp_disp_layer_dma *dma = &layer->dmas[i];
- video group.
struct xilinx_dpdma_peripheral_config pconfig = {.video_group = true,};
.slave_id = 1,
.peripheral_config = &pconfig,.peripheral_size = sizeof(pconfig),};
dmaengine_slave_config(dma->chan, &config);
diff --git a/include/linux/dma/xilinx_dpdma.h b/include/linux/dma/xilinx_dpdma.h new file mode 100644 index 000000000000..83a1377f03f8 --- /dev/null +++ b/include/linux/dma/xilinx_dpdma.h @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef __LINUX_DMA_XILINX_DPDMA_H +#define __LINUX_DMA_XILINX_DPDMA_H
+#include <linux/types.h>
+struct xilinx_dpdma_peripheral_config {
- bool video_group;
+};
+#endif /* __LINUX_DMA_XILINX_DPDMA_H */