Use kmap_local_page() instead of sg_virt() to obtain a page from the scatterlist: sg_virt() will not perform bounce buffering if the page happens to be located in high memory, which the driver may or may not be using. Suggested-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/linux-mmc/20240122073423.GA25859@xxxxxx/ Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- drivers/mmc/host/davinci_mmc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c index ee3b1a4e0848..4e9f96b1caf3 100644 --- a/drivers/mmc/host/davinci_mmc.c +++ b/drivers/mmc/host/davinci_mmc.c @@ -216,7 +216,7 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id); static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host) { host->buffer_bytes_left = sg_dma_len(host->sg); - host->buffer = sg_virt(host->sg); + host->buffer = kmap_local_page(sg_page(host->sg)); if (host->buffer_bytes_left > host->bytes_left) host->buffer_bytes_left = host->bytes_left; } @@ -261,7 +261,13 @@ static void davinci_fifo_data_trans(struct mmc_davinci_host *host, p = p + (n & 3); } } - host->buffer = p; + + if (host->buffer_bytes_left == 0) { + kunmap_local(host->buffer); + host->buffer = NULL; + } else { + host->buffer = p; + } } static void mmc_davinci_start_command(struct mmc_davinci_host *host, -- 2.34.1
