On Thu, Sep 17, 2020 at 4:12 PM Geert Uytterhoeven geert+renesas@glider.be wrote:
Before commit 9495b7e92f716ab2 ("driver core: platform: Initialize dma_parms for platform devices"), the R-Car SATA device didn't have DMA parameters. Hence the DMA boundary mask supplied by its driver was silently ignored, as __scsi_init_queue() doesn't check the return value of dma_set_seg_boundary(), and the default value of 0xffffffff was used.
Now the device has gained DMA parameters, the driver-supplied value is used, and the following warning is printed on Salvator-XS:
DMA-API: sata_rcar ee300000.sata: mapping sg segment across boundary [start=0x00000000ffffe000] [end=0x00000000ffffefff] [boundary=0x000000001ffffffe] WARNING: CPU: 5 PID: 38 at kernel/dma/debug.c:1233 debug_dma_map_sg+0x298/0x300(the range of start/end values depend on whether IOMMU support is enabled or not)
The issue here is that SATA_RCAR_DMA_BOUNDARY doesn't have bit 0 set, so any typical end value, which is odd, will trigger the check.
Fix this by increasing the DMA boundary value by 1.
This also fixes the following WRITE DMA EXT timeout issue:
# dd if=/dev/urandom of=/mnt/de1/file1-1024M bs=1M count=1024 ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen ata1.00: failed command: WRITE DMA EXT ata1.00: cmd 35/00:00:00:e6:0c/00:0a:00:00:00/e0 tag 0 dma 1310720 out res 40/00:01:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata1.00: status: { DRDY }as seen by Shimoda-san since commit 429120f3df2dba2b ("block: fix splitting segments on boundary masks").
Fixes: 8bfbeed58665dbbf ("sata_rcar: correct 'sata_rcar_sht'") Fixes: 9495b7e92f716ab2 ("driver core: platform: Initialize dma_parms for platform devices") Fixes: 429120f3df2dba2b ("block: fix splitting segments on boundary masks") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Reviewed-by: Sergei Shtylyov sergei.shtylyov@cogentembedded.com Reviewed-by: Ulf Hansson ulf.hansson@linaro.org Tested-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Tested-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Cc: stable stable@vger.kernel.org
v3:
- Add Reviewed-by, Tested-by,
- Augment description and Fixes: with Shimoda-san's problem report https://lore.kernel.org/r/1600255098-21411-1-git-send-email-yoshihiro.shimod...,
v2:
- Add Reviewed-by, Tested-by, Cc.
drivers/ata/sata_rcar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/ata/sata_rcar.c b/drivers/ata/sata_rcar.c index 141ac600b64c87ef..44b0ed8f6bb8a120 100644 --- a/drivers/ata/sata_rcar.c +++ b/drivers/ata/sata_rcar.c @@ -120,7 +120,7 @@ /* Descriptor table word 0 bit (when DTA32M = 1) */ #define SATA_RCAR_DTEND BIT(0)
-#define SATA_RCAR_DMA_BOUNDARY 0x1FFFFFFEUL +#define SATA_RCAR_DMA_BOUNDARY 0x1FFFFFFFUL
Wondering if GENMASK() here will be better to avoid such mistakes.
/* Gen2 Physical Layer Control Registers */
#define RCAR_GEN2_PHY_CTL1_REG 0x1704
2.17.1