2021-05-14 10:46:56

by Arnd Bergmann

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Subject: [PATCH v2 10/13] mwifiex: re-fix for unaligned accesses

From: Arnd Bergmann <[email protected]>

A patch from 2017 changed some accesses to DMA memory to use
get_unaligned_le32() and similar interfaces, to avoid problems
with doing unaligned accesson uncached memory.

However, the change in the mwifiex_pcie_alloc_sleep_cookie_buf()
function ended up changing the size of the access instead,
as it operates on a pointer to u8.

Change this function back to actually access the entire 32 bits.
Note that the pointer is aligned by definition because it came
from dma_alloc_coherent().

Fixes: 92c70a958b0b ("mwifiex: fix for unaligned reads")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/net/wireless/marvell/mwifiex/pcie.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 94228b316df1..46517515ba72 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -1231,7 +1231,7 @@ static int mwifiex_pcie_delete_cmdrsp_buf(struct mwifiex_adapter *adapter)
static int mwifiex_pcie_alloc_sleep_cookie_buf(struct mwifiex_adapter *adapter)
{
struct pcie_service_card *card = adapter->card;
- u32 tmp;
+ u32 *cookie;

card->sleep_cookie_vbase = dma_alloc_coherent(&card->dev->dev,
sizeof(u32),
@@ -1242,13 +1242,11 @@ static int mwifiex_pcie_alloc_sleep_cookie_buf(struct mwifiex_adapter *adapter)
"dma_alloc_coherent failed!\n");
return -ENOMEM;
}
+ cookie = (u32 *)card->sleep_cookie_vbase;
/* Init val of Sleep Cookie */
- tmp = FW_AWAKE_COOKIE;
- put_unaligned(tmp, card->sleep_cookie_vbase);
+ *cookie = FW_AWAKE_COOKIE;

- mwifiex_dbg(adapter, INFO,
- "alloc_scook: sleep cookie=0x%x\n",
- get_unaligned(card->sleep_cookie_vbase));
+ mwifiex_dbg(adapter, INFO, "alloc_scook: sleep cookie=0x%x\n", *cookie);

return 0;
}
--
2.29.2



2021-05-15 11:05:33

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v2 10/13] mwifiex: re-fix for unaligned accesses

Arnd Bergmann <[email protected]> writes:

> From: Arnd Bergmann <[email protected]>
>
> A patch from 2017 changed some accesses to DMA memory to use
> get_unaligned_le32() and similar interfaces, to avoid problems
> with doing unaligned accesson uncached memory.
>
> However, the change in the mwifiex_pcie_alloc_sleep_cookie_buf()
> function ended up changing the size of the access instead,
> as it operates on a pointer to u8.
>
> Change this function back to actually access the entire 32 bits.
> Note that the pointer is aligned by definition because it came
> from dma_alloc_coherent().
>
> Fixes: 92c70a958b0b ("mwifiex: fix for unaligned reads")
> Signed-off-by: Arnd Bergmann <[email protected]>

Via which tree should this go? I assume it will go via some other tree
so:

Acked-by: Kalle Valo <[email protected]>

--
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2021-05-15 11:42:23

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH v2 10/13] mwifiex: re-fix for unaligned accesses

On Sat, May 15, 2021 at 8:22 AM Kalle Valo <[email protected]> wrote:
> Arnd Bergmann <[email protected]> writes:
> > From: Arnd Bergmann <[email protected]>
> >
> > A patch from 2017 changed some accesses to DMA memory to use
> > get_unaligned_le32() and similar interfaces, to avoid problems
> > with doing unaligned accesson uncached memory.
> >
> > However, the change in the mwifiex_pcie_alloc_sleep_cookie_buf()
> > function ended up changing the size of the access instead,
> > as it operates on a pointer to u8.
> >
> > Change this function back to actually access the entire 32 bits.
> > Note that the pointer is aligned by definition because it came
> > from dma_alloc_coherent().
> >
> > Fixes: 92c70a958b0b ("mwifiex: fix for unaligned reads")
> > Signed-off-by: Arnd Bergmann <[email protected]>
>
> Via which tree should this go? I assume it will go via some other tree
> so:
>
> Acked-by: Kalle Valo <[email protected]>

I have queued the series in the asm-generic tree for 5.14, as the patches
that depend on this one are a little too invasive for 5.13 at this point.

If you think this fix should be in 5.13, please take it through your tree.

Arnd