On Thu, Sep 17, 2020 at 4:12 PM Geert Uytterhoeven <geert+renesas@xxxxxxxxx> 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@xxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Reviewed-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> > Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> > Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > Cc: stable <stable@xxxxxxxxxxxxxxx> > --- > 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.shimoda.uh@xxxxxxxxxxx, > > 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 > -- With Best Regards, Andy Shevchenko