Re: [PATCH v3 6/7] USB: ohci-at91: add usb_clk for transition tocommon clk framework

From: boris brezillon
Date: Tue Jul 16 2013 - 15:15:43 EST


On 16/07/2013 20:47, Alan Stern wrote:
On Tue, 16 Jul 2013, boris brezillon wrote:

+ uclk = clk_get(&pdev->dev, "usb_clk");
+ if (IS_ERR(uclk)) {
+ uclk = NULL;
+ dev_warn(&pdev->dev, "failed to get usb_clk\n");
+ }
Is this really what you want for backward compatibility?
Here are some proposition to remove the warning message:

1) replace it with a dev_info and change the message:
dev_info(&pdev->dev, "failed to get usb_clk (most likely using old
at91 clk implementation)\n");
2) drop the log and silently ignore the missing clk (I'm not a big fan
of this solution
as it may lead to some errors if we're using new clk implem and the
clock is really missing)
3) rework the current clk_set_rate function to accept clk_set_rate on
usb clk and add clk_lookup entries
for the usb clk (I'm not a big fan of this solution neither as this
modifications will only be used for a short time
until the transition to common clk framework is completed).
Another possibility is to combine this change with the clock
implementation update, and do them in a single patch. Then backward
compatibility would not be an issue.
Yes, that was one of the question I asked in the cover-letter.

I think I'll move these patches in the "move to common clk" series.

Thanks
Alan Stern


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