Re: [PATCH 3/3] jz4740_fb: fix DMA API abuse
From: Bartlomiej Zolnierkiewicz <hidden>
Date: 2019-06-07 12:21:09
Also in:
linux-mips, lkml
On 5/9/19 7:38 PM, Christoph Hellwig wrote:
Virtual addresses return from dma(m)_alloc_coherent are opaque in what backs then, and drivers must not poke into them. Switch the driver to use the generic DMA API mmap helper to avoid these problems.
Change itself looks fine but the patch description doesn't match what the patch is actually doing (there is no conversion to DMA API helper because the driver is already using it). Please correct it. Thank you.
quoted hunk ↗ jump to hunk
Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/video/fbdev/jz4740_fb.c | 7 ------- 1 file changed, 7 deletions(-)diff --git a/drivers/video/fbdev/jz4740_fb.c b/drivers/video/fbdev/jz4740_fb.c index b57df83fdbd3..b95cdfa9e0a1 100644 --- a/drivers/video/fbdev/jz4740_fb.c +++ b/drivers/video/fbdev/jz4740_fb.c@@ -466,7 +466,6 @@ static int jzfb_alloc_devmem(struct jzfb *jzfb) { int max_videosize = 0; struct fb_videomode *mode = jzfb->pdata->modes; - void *page; int i; for (i = 0; i < jzfb->pdata->num_modes; ++mode, ++i) {@@ -491,12 +490,6 @@ static int jzfb_alloc_devmem(struct jzfb *jzfb) if (!jzfb->vidmem) goto err_free_framedesc; - for (page = jzfb->vidmem; - page < jzfb->vidmem + PAGE_ALIGN(jzfb->vidmem_size); - page += PAGE_SIZE) { - SetPageReserved(virt_to_page(page)); - } - jzfb->framedesc->next = jzfb->framedesc_phys; jzfb->framedesc->addr = jzfb->vidmem_phys; jzfb->framedesc->id = 0xdeafbead;
Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics