| Message ID | 20240924210123.2288529-1-linux@roeck-us.net |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: core: Only set maximum DMA segment size if DMA is supported | expand |
On Tue, Sep 24, 2024 at 02:01:23PM -0700, Guenter Roeck wrote: > Since upstream commit 334304ac2bac ("dma-mapping: don't return errors > from dma_set_max_seg_size") calling dma_set_max_seg_size() on a device > not supporting DMA results in a warning traceback. This is seen when > booting the sifive_u machine from SD. The underlying SPI controller > (sifive,spi0 compatible) explicitly sets dma_mask to NULL. > > Avoid the backtrace by only calling dma_set_max_seg_size() if DMA is > supported. Technicall this looks fine, although it would be nice avoid the overly long line. Reviewed-by: Christoph Hellwig <hch@lst.de>
On 24/09/2024 10:01 pm, Guenter Roeck wrote: > Since upstream commit 334304ac2bac ("dma-mapping: don't return errors > from dma_set_max_seg_size") calling dma_set_max_seg_size() on a device > not supporting DMA results in a warning traceback. This is seen when > booting the sifive_u machine from SD. The underlying SPI controller > (sifive,spi0 compatible) explicitly sets dma_mask to NULL. Hmm, that driver probably shouldn't be doing that, but either way it's not actually relevant to this check - what's significant is that when the MMC host device is an "mmc-spi-slot" instance, its mmc_dev() ends up being the SPI *device* itself, not the grandparent SPI controller. Thus the patch itself is appropriate on the basis that MMC hosts may exist on non-DMA-capable buses, so the subsystem needs to consider that. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Avoid the backtrace by only calling dma_set_max_seg_size() if DMA is > supported. > > Cc: Christoph Hellwig <hch@lst.de> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Ulf Hansson <ulf.hansson@linaro.org> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/mmc/core/queue.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index d0b3ca8a11f0..4d6844261912 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -388,7 +388,8 @@ static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq, > > blk_queue_rq_timeout(mq->queue, 60 * HZ); > > - dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); > + if (mmc_dev(host)->dma_parms) > + dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); > > INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler); > INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index d0b3ca8a11f0..4d6844261912 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -388,7 +388,8 @@ static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq, blk_queue_rq_timeout(mq->queue, 60 * HZ); - dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); + if (mmc_dev(host)->dma_parms) + dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue)); INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler); INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
Since upstream commit 334304ac2bac ("dma-mapping: don't return errors from dma_set_max_seg_size") calling dma_set_max_seg_size() on a device not supporting DMA results in a warning traceback. This is seen when booting the sifive_u machine from SD. The underlying SPI controller (sifive,spi0 compatible) explicitly sets dma_mask to NULL. Avoid the backtrace by only calling dma_set_max_seg_size() if DMA is supported. Cc: Christoph Hellwig <hch@lst.de> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/mmc/core/queue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)