media: cx25821: Fix a bug when reallocating some dma memory

[ Upstream commit b2de3643c5024fc4fd128ba7767c7fb8b714bea7 ]

This function looks like a realloc.

However, if 'risc->cpu != NULL', the memory will be freed, but never
reallocated with the bigger 'size'.
Explicitly set 'risc->cpu' to NULL, so that the reallocation is
correctly performed a few lines below.

[hverkuil: NULL != risc->cpu -> risc->cpu]

Fixes: 5ede94c70553 ("[media] cx25821: remove bogus btcx_risc dependency)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/pci/cx25821/cx25821-core.c b/drivers/media/pci/cx25821/cx25821-core.c
index 54398d8a4696c3ab616006a3b1c6deb6bbc87167..b43cf85ed5f0550352aa8d4a7bdb31eaf778b2dd 100644 (file)
--- a/drivers/media/pci/cx25821/cx25821-core.c
+++ b/drivers/media/pci/cx25821/cx25821-core.c
@@ -990,8 +990,10 @@ int cx25821_riscmem_alloc(struct pci_dev *pci,
        __le32 *cpu;
        dma_addr_t dma = 0;
 
-       if (NULL != risc->cpu && risc->size < size)
+       if (risc->cpu && risc->size < size) {
                pci_free_consistent(pci, risc->size, risc->cpu, risc->dma);
+               risc->cpu = NULL;
+       }
        if (NULL == risc->cpu) {
                cpu = pci_zalloc_consistent(pci, size, &dma);
                if (NULL == cpu)