[U-Boot] CONFIG_USB_EHCI_HCD breaks xHCI drivers even on DM

[Masahiro Yamada]

Hi Marek, Simon.


Basically, Driver Mode allows us to enable multiple drivers without
affecting each other
because drivers are configured in probe functions
instead of compile-time configuration by #ifdef:s

With DM, I think it is legitimate to enable EHCI and xHCI at the same time,
but it is not actually true.


If CONFIG_USB_EHCI_HCD is disabled, xHCI drivers work fine,
but with CONFIG_USB_EHCI_HCD enabled, xHCI drivers go wrong as follows:

=> fatload usb 0 82000000 Image
reading Image
WARN halted endpoint, queueing URB anyway.
Unexpected XHCI event TRB, skipping... (3fb54090 00000001 13000000 01008401)
BUG: failure at
/home/masahiro/workspace/u-boot-yamada/drivers/usb/host/xhci-ring.c:489/abort_td()!
BUG!
### ERROR ### Please RESET the board ###


Here, "Image" is larger than 10MB.



I narrowed down the cause of the problem
in the following code in common/usb_storage.c


#ifdef CONFIG_USB_EHCI_HCD
/*
 * The U-Boot EHCI driver can handle any transfer length as long as there is
 * enough free heap space left, but the SCSI READ(10) and WRITE(10) commands are
 * limited to 65535 blocks.
 */
#define USB_MAX_XFER_BLK        65535
#else
#define USB_MAX_XFER_BLK        20
#endif



Of course, this ifdef is not acceptable in Driver Model,
so we need to fix it somehow.


I am not familiar with that part at all,
but I just aligned the value to the lowest common denominator (20)
as follows:



diff --git a/common/usb_storage.c b/common/usb_storage.c
index 03171f74cb02..b6d16e3dead3 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -100,16 +100,7 @@ struct us_data {
        trans_cmnd      transport;              /* transport routine */
 };

-#ifdef CONFIG_USB_EHCI_HCD
-/*
- * The U-Boot EHCI driver can handle any transfer length as long as there is
- * enough free heap space left, but the SCSI READ(10) and WRITE(10)
commands are
- * limited to 65535 blocks.
- */
-#define USB_MAX_XFER_BLK       65535
-#else
 #define USB_MAX_XFER_BLK       20
-#endif

 #ifndef CONFIG_BLK
 static struct us_data usb_stor[USB_MAX_STOR_DEV];



With with, both EHCI and xHCI seem to work
but I am not sure if this is the right way to fix the problem.

Thought?



-- 
Best Regards
Masahiro Yamada