[U-Boot] [PATCH] usb: ehci: Fix accessors for big-endian platforms and descriptors

Alexey Brodkin Alexey.Brodkin at synopsys.com
Fri Nov 17 13:26:30 UTC 2017


Commit 9000eddbae0d ("drivers/usb/ehci: Use platform-specific accessors")
broke USB 2.0 on big-endian platforms because for them writel/readl()
does automatic conversion of BE data to LE.

Proper implementation requires to use "raw" variant of these accessors
which read/write data without messing with endianess.

While at it replace cpu_to_be32() to be32_to_cpu() in readl() to
keep sane semantics.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
Cc: Marek Vasut <marex at denx.de>
Reported-by: Vladimir Boroda <boroda at yahoo.com>
---
 drivers/usb/host/ehci.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 7c39becd247e..18692b732ea6 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -101,11 +101,11 @@ struct usb_linux_config_descriptor {
 } __attribute__ ((packed));
 
 #if defined CONFIG_EHCI_DESC_BIG_ENDIAN
-#define ehci_readl(x)		cpu_to_be32(readl(x))
-#define ehci_writel(a, b)	writel(cpu_to_be32(b), a)
+#define ehci_readl(x)		be32_to_cpu(__raw_readl(x))
+#define ehci_writel(a, b)	__raw_writel(cpu_to_be32(b), a)
 #else
-#define ehci_readl(x)		cpu_to_le32(readl(x))
-#define ehci_writel(a, b)	writel(cpu_to_le32(b), a)
+#define ehci_readl(x)		readl(x)
+#define ehci_writel(a, b)	writel(b, a)
 #endif
 
 #if defined CONFIG_EHCI_MMIO_BIG_ENDIAN
-- 
2.7.5



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