openwrt/target/linux/bcm27xx/patches-6.6/950-1166-dmaengine-dw-axi-dmac-Honour-snps-block-size.patch
Álvaro Fernández Rojas 0171157d45 bcm27xx: update to latest RPi patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.44..rpi-6.6.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-08-06 18:38:00 +02:00

53 lines
1.9 KiB
Diff

From 475cddaba6b02584157e1c128a5a6858770a3d06 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Wed, 10 Jul 2024 14:47:17 +0100
Subject: [PATCH 1166/1215] dmaengine: dw-axi-dmac: Honour snps,block-size
The snps,block-size DT property declares the maximum block size for each
channel of the dw-axi-dmac. However, the driver ignores these when
setting max_seg_size and uses MAX_BLOCK_SIZE (4096) instead.
To take advantage of the efficiencies of larger blocks, calculate the
minimum block size across all channels and use that instead.
See: https://github.com/raspberrypi/linux/issues/6256
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -1470,6 +1470,7 @@ static int dw_probe(struct platform_devi
struct dw_axi_dma *dw;
struct dw_axi_dma_hcfg *hdata;
struct reset_control *resets;
+ unsigned int max_seg_size;
unsigned int flags;
u32 i;
int ret;
@@ -1585,9 +1586,21 @@ static int dw_probe(struct platform_devi
* Synopsis DesignWare AxiDMA datasheet mentioned Maximum
* supported blocks is 1024. Device register width is 4 bytes.
* Therefore, set constraint to 1024 * 4.
+ * However, if all channels specify a greater value, use that instead.
*/
+
dw->dma.dev->dma_parms = &dw->dma_parms;
- dma_set_max_seg_size(&pdev->dev, MAX_BLOCK_SIZE);
+ max_seg_size = UINT_MAX;
+ for (i = 0; i < dw->hdata->nr_channels; i++) {
+ unsigned int block_size = chip->dw->hdata->block_size[i];
+
+ if (!block_size)
+ block_size = MAX_BLOCK_SIZE;
+ max_seg_size = min(block_size, max_seg_size);
+ }
+
+ dma_set_max_seg_size(&pdev->dev, max_seg_size);
+
platform_set_drvdata(pdev, chip);
pm_runtime_enable(chip->dev);