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From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: barebox@lists.infradead.org
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>
Subject: [PATCH 07/25] usb: xhci-hcd: Don't try to DMA sync if buffer is NULL
Date: Tue, 19 Feb 2019 23:29:12 -0800	[thread overview]
Message-ID: <20190220072930.14300-8-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20190220072930.14300-1-andrew.smirnov@gmail.com>

Driver's .submit_control() callback can and will be called with buffer
set to NULL (and length set to 0), so we need to make sure that we
don't try to DMA sync the buffer in that case. Add appropriate gurads
to make sure that doesn't happen.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/usb/host/xhci-hcd.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 91ddcbb30..657a49f8a 100644
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -1200,10 +1200,12 @@ static int xhci_submit_control(struct usb_device *udev, unsigned long pipe,
 			return ret;
 	}
 
-	/* Pass ownership of data buffer to device */
-	dma_sync_single_for_device((unsigned long)buffer, length,
-				   (req->requesttype & USB_DIR_IN) ?
-				   DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	if (length > 0) {
+		/* Pass ownership of data buffer to device */
+		dma_sync_single_for_device((unsigned long)buffer, length,
+					   (req->requesttype & USB_DIR_IN) ?
+					   DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	}
 
 	/* Setup TRB */
 	memset(&trb, 0, sizeof(union xhci_trb));
@@ -1259,10 +1261,13 @@ static int xhci_submit_control(struct usb_device *udev, unsigned long pipe,
 	xhci_print_trb(xhci, &trb, "Response Status");
 
 dma_regain:
-	/* Regain ownership of data buffer from device */
-	dma_sync_single_for_cpu((unsigned long)buffer, length,
-				(req->requesttype & USB_DIR_IN) ?
-				DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	if (length > 0) {
+		/* Regain ownership of data buffer from device */
+		dma_sync_single_for_cpu((unsigned long)buffer, length,
+					(req->requesttype & USB_DIR_IN) ?
+					DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	}
+
 	if (ret < 0)
 		return ret;
 
-- 
2.20.1


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  parent reply	other threads:[~2019-02-20  7:29 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-20  7:29 [PATCH 00/25] i.MX8MQ USB support Andrey Smirnov
2019-02-20  7:29 ` [PATCH 01/25] usb: xhci-hcd: Tabify the file Andrey Smirnov
2019-02-20  7:29 ` [PATCH 02/25] usb: xhci-hcd: Do not zero out DMA coherent memory Andrey Smirnov
2019-02-20  9:29   ` Yann Sionneau
2019-02-20 18:54     ` Andrey Smirnov
2019-02-23 10:16     ` Sam Ravnborg
2019-02-20  7:29 ` [PATCH 03/25] usb: xhci-hcd: Cast ~XHCI_IRQS to u32 Andrey Smirnov
2019-02-20  7:29 ` [PATCH 04/25] usb: xhci-hcd: Make sure to initialize xhci->rings_list Andrey Smirnov
2019-02-20  7:29 ` [PATCH 05/25] usb: xhci-hcd: Drop pointless bitwise or Andrey Smirnov
2019-02-20  7:29 ` [PATCH 06/25] usb: xhci-hcd: Add support for 64-byte context size Andrey Smirnov
2019-02-20  7:29 ` Andrey Smirnov [this message]
2019-02-20  7:29 ` [PATCH 08/25] usb: xhci-hcd: Always wait for "Response Data" completion Andrey Smirnov
2019-02-20  7:29 ` [PATCH 09/25] usb: xhci-hcd: Convert xhci_submit_normal() to use dma_map_single() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 10/25] usb: xhci-hcd: Convert xhci_submit_control() " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 11/25] usb: xhci-hcd: Simplify TRB initialization code Andrey Smirnov
2019-02-20  7:29 ` [PATCH 12/25] usb: xhci-hcd: Drop 'dma' field from struct xhci_hcd Andrey Smirnov
2019-02-20  7:29 ` [PATCH 13/25] usb: xhci-hcd: Check usb_pipein(pipe) only once in xhci_submit_normal() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 14/25] usb: xhci-hcd: Initialize TRT flag for xHCI >= 1.0 Andrey Smirnov
2019-02-20  7:29 ` [PATCH 15/25] usb: xhci-hcd: Simplify route string building loop Andrey Smirnov
2019-02-20  7:29 ` [PATCH 16/25] usb: xhci-hcd: Make use of lo_hi_readq/writeq() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 17/25] phy: core: Assume EPROBE_DEFER in of_phy_provider_lookup() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 18/25] phy: Port i.MX8MQ USB PHY driver from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 19/25] clk: Drop separate definitions of clk_put() Andrey Smirnov
2019-02-20  7:29 ` [PATCH 20/25] include/usb: Import USB_SPEED_SUPER_PLUS from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 21/25] clk: Import a subset of clk_bulk API " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 22/25] usb: Import DWC3 USB controller driver " Andrey Smirnov
2019-02-20  7:29 ` [PATCH 23/25] lib: Port basic Linux kernel NLS functions Andrey Smirnov
2019-02-20  7:29 ` [PATCH 24/25] usb: Port Microchip USB251x USB hub driver from Linux Andrey Smirnov
2019-02-20  7:29 ` [PATCH 25/25] usb: usb251xb: add usb data lane port swap feature Andrey Smirnov
2019-02-22  7:27 ` [PATCH 00/25] i.MX8MQ USB support Sascha Hauer

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