On 06/09/17 05:44, Shawn Lin wrote: > + Seraphime > > On 2017/9/6 3:47, Pavel Machek wrote: >> Hi! >> >> I tried to write to the MMC card; process hung and I got this in the >> dmesg. > > > A similar report for 4.13 cycle was here: > > https://lkml.org/lkml/2017/8/10/824 > > Seems 4.13-rc4 was already broken for that but unfortuantely I didn't > reproduce that. So maybe Seraphime can do git-bisect as he said "I get > it everytime" for which I assume it could be easy for him to find out > the problematic commit? > One obvious weakness in the new mmc_init_request() is the possibility that it might be called before card->bouncesz is set up. That could result in bouncing being done but mq_rq->bounce_sg is null. This might help: diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index affa7370ba82..ad3e53e63abb 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -242,6 +242,8 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT; + card->bouncesz = mmc_queue_calc_bouncesz(host); + mq->card = card; mq->queue = blk_alloc_queue(GFP_KERNEL); if (!mq->queue) @@ -265,7 +267,6 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, if (mmc_can_erase(card)) mmc_queue_setup_discard(mq->queue, card); - card->bouncesz = mmc_queue_calc_bouncesz(host); if (card->bouncesz) { blk_queue_max_hw_sectors(mq->queue, card->bouncesz / 512); blk_queue_max_segments(mq->queue, card->bouncesz / 512); Another unrelated issue with mmc_init_request() is that mmc_exit_request() is not called if mmc_init_request() fails, which means mmc_init_request() must free anything it allocates when it fails. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
