Re: [PATCH] usb: musb: Fix fifo reads for dm816x with musb_dsps

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org> [150319 10:50]:
> On 03/19/2015 04:30 PM, Sergei Shtylyov wrote:
> >>--- a/drivers/usb/musb/musb_dsps.c
> >>+++ b/drivers/usb/musb/musb_dsps.c
> >>@@ -655,6 +655,36 @@ static int dsps_musb_reset(struct musb *musb)
> >>      return !session_restart;
> >>  }
> >>
> >>+/* Similar to am35x, dm81xx support only 32-bit read operation */
> >>+static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
> >>+{
> >>+    void __iomem *fifo = hw_ep->fifo;
> >>+    u32        val;
> >>+    int        i;
> >>+
> >>+    /* Read for 32bit-aligned destination address */
> >>+    if (likely((0x03 & (unsigned long)dst) == 0) && len >= 4) {
> >>+        readsl(fifo, dst, len >> 2);
> >>+        dst += len & ~0x03;
> >>+        len &= 0x03;
> >>+    }
> >>+    /*
> >>+     * Now read the remaining 1 to 3 byte or complete length if
> >>+     * unaligned address.
> >>+     */
> 
> >   This comment seems misplaced, it belongs before the next *if*.
> 
> >>+    if (len > 4) {
> >>+        for (i = 0; i < (len >> 2); i++) {
> >>+            *(u32 *)dst = musb_readl(fifo, 0);
> >>+            dst += 4;
> >>+        }
> 
> >    Not sure how this is different to using readsl().
> 
>    Ah, the default implementation of musb_readl() uses __raw_readl().
> So you'd probably want to keep this loop, not readsl() call.

Not sure I follow you here.. Also include/asm-generic/io.h readsl()
uses __raw_readl()?

It seems things work with what I posted, so a readsl() loop, then
just read the remaining 1 to 3 bytes.

Regards,

Tony 
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