2020-01-07 21:48:07

by Arnd Bergmann

[permalink] [raw]
Subject: [PATCH] drm: meson: fix address type confusion

Casting a pointer to dma_addr_t produces a warning:

drivers/gpu/drm/meson/meson_rdma.c: In function 'meson_rdma_free':
drivers/gpu/drm/meson/meson_rdma.c:59:25: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
priv->rdma.addr_phys = (dma_addr_t)NULL;

In this case, it's worse because the variable name has the suffix
'_phys', which often indicates a phys_addr_t rather than dma_addr_t,
i.e. yet another incompatible type.

Change it to use consistent naming and avoid NULL.

Fixes: 63fba242c464 ("drm/meson: add RDMA module driver")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/gpu/drm/meson/meson_drv.h | 2 +-
drivers/gpu/drm/meson/meson_rdma.c | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_drv.h b/drivers/gpu/drm/meson/meson_drv.h
index f9a0c8e9d4d0..04fdf3826643 100644
--- a/drivers/gpu/drm/meson/meson_drv.h
+++ b/drivers/gpu/drm/meson/meson_drv.h
@@ -135,7 +135,7 @@ struct meson_drm {
} venc;

struct {
- dma_addr_t addr_phys;
+ dma_addr_t addr_dma;
uint32_t *addr;
unsigned int offset;
} rdma;
diff --git a/drivers/gpu/drm/meson/meson_rdma.c b/drivers/gpu/drm/meson/meson_rdma.c
index 25b34b1e72a7..130382178c63 100644
--- a/drivers/gpu/drm/meson/meson_rdma.c
+++ b/drivers/gpu/drm/meson/meson_rdma.c
@@ -27,7 +27,7 @@ int meson_rdma_init(struct meson_drm *priv)
/* Allocate a PAGE buffer */
priv->rdma.addr =
dma_alloc_coherent(priv->dev, SZ_4K,
- &priv->rdma.addr_phys,
+ &priv->rdma.addr_dma,
GFP_KERNEL);
if (!priv->rdma.addr)
return -ENOMEM;
@@ -47,16 +47,16 @@ int meson_rdma_init(struct meson_drm *priv)

void meson_rdma_free(struct meson_drm *priv)
{
- if (!priv->rdma.addr && !priv->rdma.addr_phys)
+ if (!priv->rdma.addr && !priv->rdma.addr_dma)
return;

meson_rdma_stop(priv);

dma_free_coherent(priv->dev, SZ_4K,
- priv->rdma.addr, priv->rdma.addr_phys);
+ priv->rdma.addr, priv->rdma.addr_dma);

priv->rdma.addr = NULL;
- priv->rdma.addr_phys = (dma_addr_t)NULL;
+ priv->rdma.addr_dma = (dma_addr_t)0;
}

void meson_rdma_setup(struct meson_drm *priv)
@@ -118,11 +118,11 @@ void meson_rdma_flush(struct meson_drm *priv)
meson_rdma_stop(priv);

/* Start of Channel 1 register writes buffer */
- writel(priv->rdma.addr_phys,
+ writel(priv->rdma.addr_dma,
priv->io_base + _REG(RDMA_AHB_START_ADDR_1));

/* Last byte on Channel 1 register writes buffer */
- writel(priv->rdma.addr_phys + (priv->rdma.offset * RDMA_DESC_SIZE) - 1,
+ writel(priv->rdma.addr_dma + (priv->rdma.offset * RDMA_DESC_SIZE) - 1,
priv->io_base + _REG(RDMA_AHB_END_ADDR_1));

/* Trigger Channel 1 on VSYNC event */
--
2.20.0


2020-01-08 10:23:45

by Neil Armstrong

[permalink] [raw]
Subject: Re: [PATCH] drm: meson: fix address type confusion

On 07/01/2020 22:46, Arnd Bergmann wrote:
> Casting a pointer to dma_addr_t produces a warning:
>
> drivers/gpu/drm/meson/meson_rdma.c: In function 'meson_rdma_free':
> drivers/gpu/drm/meson/meson_rdma.c:59:25: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
> priv->rdma.addr_phys = (dma_addr_t)NULL;
>
> In this case, it's worse because the variable name has the suffix
> '_phys', which often indicates a phys_addr_t rather than dma_addr_t,
> i.e. yet another incompatible type.
>
> Change it to use consistent naming and avoid NULL.
>
> Fixes: 63fba242c464 ("drm/meson: add RDMA module driver")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/gpu/drm/meson/meson_drv.h | 2 +-
> drivers/gpu/drm/meson/meson_rdma.c | 12 ++++++------
> 2 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_drv.h b/drivers/gpu/drm/meson/meson_drv.h
> index f9a0c8e9d4d0..04fdf3826643 100644
> --- a/drivers/gpu/drm/meson/meson_drv.h
> +++ b/drivers/gpu/drm/meson/meson_drv.h
> @@ -135,7 +135,7 @@ struct meson_drm {
> } venc;
>
> struct {
> - dma_addr_t addr_phys;
> + dma_addr_t addr_dma;
> uint32_t *addr;
> unsigned int offset;
> } rdma;
> diff --git a/drivers/gpu/drm/meson/meson_rdma.c b/drivers/gpu/drm/meson/meson_rdma.c
> index 25b34b1e72a7..130382178c63 100644
> --- a/drivers/gpu/drm/meson/meson_rdma.c
> +++ b/drivers/gpu/drm/meson/meson_rdma.c
> @@ -27,7 +27,7 @@ int meson_rdma_init(struct meson_drm *priv)
> /* Allocate a PAGE buffer */
> priv->rdma.addr =
> dma_alloc_coherent(priv->dev, SZ_4K,
> - &priv->rdma.addr_phys,
> + &priv->rdma.addr_dma,
> GFP_KERNEL);
> if (!priv->rdma.addr)
> return -ENOMEM;
> @@ -47,16 +47,16 @@ int meson_rdma_init(struct meson_drm *priv)
>
> void meson_rdma_free(struct meson_drm *priv)
> {
> - if (!priv->rdma.addr && !priv->rdma.addr_phys)
> + if (!priv->rdma.addr && !priv->rdma.addr_dma)
> return;
>
> meson_rdma_stop(priv);
>
> dma_free_coherent(priv->dev, SZ_4K,
> - priv->rdma.addr, priv->rdma.addr_phys);
> + priv->rdma.addr, priv->rdma.addr_dma);
>
> priv->rdma.addr = NULL;
> - priv->rdma.addr_phys = (dma_addr_t)NULL;
> + priv->rdma.addr_dma = (dma_addr_t)0;
> }
>
> void meson_rdma_setup(struct meson_drm *priv)
> @@ -118,11 +118,11 @@ void meson_rdma_flush(struct meson_drm *priv)
> meson_rdma_stop(priv);
>
> /* Start of Channel 1 register writes buffer */
> - writel(priv->rdma.addr_phys,
> + writel(priv->rdma.addr_dma,
> priv->io_base + _REG(RDMA_AHB_START_ADDR_1));
>
> /* Last byte on Channel 1 register writes buffer */
> - writel(priv->rdma.addr_phys + (priv->rdma.offset * RDMA_DESC_SIZE) - 1,
> + writel(priv->rdma.addr_dma + (priv->rdma.offset * RDMA_DESC_SIZE) - 1,
> priv->io_base + _REG(RDMA_AHB_END_ADDR_1));
>
> /* Trigger Channel 1 on VSYNC event */
>

Acked-by: Neil Armstrong <[email protected]>

Applying to drm-misc-fixes

Thanks,
Neil