linux-kernel - [PATCH 7/7] usb: musb/ux500: remove duplicate check for dma_is

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Message-Id: <1453998206-3490016-3-git-send-email-arnd@arndb.de>
Date:	Thu, 28 Jan 2016 17:23:15 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	Felipe Balbi <balbi@...nel.org>
Cc:	linux-arm-kernel@...ts.infradead.org,
	Arnd Bergmann <arnd@...db.de>, Felipe Balbi <balbi@...com>,
	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
	Robert Jarzmik <robert.jarzmik@...e.fr>,
	Haojian Zhuang <haojian.zhuang@...il.com>,
	Daniel Mack <daniel@...que.org>,
	Imre Kaloz <kaloz@...nwrt.org>,
	Krzysztof Halasa <khalasa@...p.pl>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH 7/7] usb: musb/ux500: remove duplicate check for dma_is_compatible

When dma_addr_t is 64-bit, we get a warning about an invalid cast
in the call to ux500_dma_is_compatible() from ux500_dma_channel_program():

drivers/usb/musb/ux500_dma.c: In function 'ux500_dma_channel_program':
drivers/usb/musb/ux500_dma.c:210:51: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
  if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))

The problem is that ux500_dma_is_compatible() is called from the
main musb driver on the virtual address, but here we pass in a
DMA address, so the types are fundamentally different but it works
because the function only checks the alignment of the buffer and
that is the same.

We could work around this by adding another cast, but I have checked
that the buffer we get passed here is already checked before it
gets mapped, so the second check seems completely unnecessary
and removing it must be the cleanest solution.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/usb/musb/ux500_dma.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/usb/musb/ux500_dma.c b/drivers/usb/musb/ux500_dma.c
index d0b6a1cd7f62..c92a295049ad 100644
--- a/drivers/usb/musb/ux500_dma.c
+++ b/drivers/usb/musb/ux500_dma.c
@@ -207,9 +207,6 @@ static int ux500_dma_channel_program(struct dma_channel *channel,
 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
 		channel->status == MUSB_DMA_STATUS_BUSY);
 
-	if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
-		return false;
-
 	channel->status = MUSB_DMA_STATUS_BUSY;
 	channel->actual_len = 0;
 	ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
-- 
2.7.0