[4/7] soc: fsl: qe: replace spin_event_timeout by readx_poll_timeout_atomic
diff mbox series

Message ID 20191018125234.21825-5-linux@rasmusvillemoes.dk
State Not Applicable
Headers show
Series
  • towards QE support on ARM
Related show

Commit Message

Rasmus Villemoes Oct. 18, 2019, 12:52 p.m. UTC
In preparation for allowing QE to be built for architectures other
than ppc, use the generic readx_poll_timeout_atomic() helper from
iopoll.h rather than the ppc-only spin_event_timeout().

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 drivers/soc/fsl/qe/qe.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

Christoph Hellwig Oct. 18, 2019, 4:08 p.m. UTC | #1
On Fri, Oct 18, 2019 at 02:52:31PM +0200, Rasmus Villemoes wrote:
>  	/* wait for the QE_CR_FLG to clear */
> -	ret = spin_event_timeout((ioread32be(&qe_immr->cp.cecr) & QE_CR_FLG) == 0,
> -				 100, 0);
> -	/* On timeout (e.g. failure), the expression will be false (ret == 0),
> -	   otherwise it will be true (ret == 1). */
> +	ret = readx_poll_timeout_atomic(ioread32be, &qe_immr->cp.cecr, val, (val & QE_CR_FLG) == 0,

This creates an overly long line.

Btw, given how few users of spin_event_timeout we have it might be good
idea to just kill it entirely.
Rasmus Villemoes Oct. 24, 2019, 8:32 a.m. UTC | #2
On 18/10/2019 18.08, Christoph Hellwig wrote:
> On Fri, Oct 18, 2019 at 02:52:31PM +0200, Rasmus Villemoes wrote:
>>  	/* wait for the QE_CR_FLG to clear */
>> -	ret = spin_event_timeout((ioread32be(&qe_immr->cp.cecr) & QE_CR_FLG) == 0,
>> -				 100, 0);
>> -	/* On timeout (e.g. failure), the expression will be false (ret == 0),
>> -	   otherwise it will be true (ret == 1). */
>> +	ret = readx_poll_timeout_atomic(ioread32be, &qe_immr->cp.cecr, val, (val & QE_CR_FLG) == 0,
> 
> This creates an overly long line.

Yeah, readx_poll_timeout_atomic is a mouthful, and then one also has to
put in the name of the accessor... I'll wrap it when I respin the
series, thanks.

> Btw, given how few users of spin_event_timeout we have it might be good
> idea to just kill it entirely.

Maybe. That's for the ppc folks to comment on; the iopoll.h helpers are
not completely equivalent (because obviously they don't read tbl
directly). Maybe the generic versions should be taught
spin_begin/spin_end/spin_cpu_relax so at least that part would be
drop-in replacement.

Rasmus
Michael Ellerman Oct. 30, 2019, 12:36 a.m. UTC | #3
Rasmus Villemoes <linux@rasmusvillemoes.dk> writes:
> On 18/10/2019 18.08, Christoph Hellwig wrote:
>> On Fri, Oct 18, 2019 at 02:52:31PM +0200, Rasmus Villemoes wrote:
>>>  	/* wait for the QE_CR_FLG to clear */
>>> -	ret = spin_event_timeout((ioread32be(&qe_immr->cp.cecr) & QE_CR_FLG) == 0,
>>> -				 100, 0);
>>> -	/* On timeout (e.g. failure), the expression will be false (ret == 0),
>>> -	   otherwise it will be true (ret == 1). */
>>> +	ret = readx_poll_timeout_atomic(ioread32be, &qe_immr->cp.cecr, val, (val & QE_CR_FLG) == 0,
>> 
>> This creates an overly long line.
>
> Yeah, readx_poll_timeout_atomic is a mouthful, and then one also has to
> put in the name of the accessor... I'll wrap it when I respin the
> series, thanks.
>
>> Btw, given how few users of spin_event_timeout we have it might be good
>> idea to just kill it entirely.
>
> Maybe. That's for the ppc folks to comment on; the iopoll.h helpers are
> not completely equivalent (because obviously they don't read tbl
> directly).

AFAICS it was added by and only ever used by Freescale folks, most of
whom have now moved on to other things.

I'd be happy to see it replaced with something generic.

I created an issue in our github to remind us to do that cleanup. Though
in practice that probably just means we'll never get around to it:

  https://github.com/linuxppc/issues/issues/280

> Maybe the generic versions should be taught
> spin_begin/spin_end/spin_cpu_relax so at least that part would be
> drop-in replacement.

That would be nice. Though TBH the intersection of platforms that use
spin_event_timeout() and also define a non-empty spin_begin() etc. is
close to if not zero.

cheers

Patch
diff mbox series

diff --git a/drivers/soc/fsl/qe/qe.c b/drivers/soc/fsl/qe/qe.c
index 60bf047001be..d18b25a685ca 100644
--- a/drivers/soc/fsl/qe/qe.c
+++ b/drivers/soc/fsl/qe/qe.c
@@ -22,6 +22,7 @@ 
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/ioport.h>
+#include <linux/iopoll.h>
 #include <linux/crc32.h>
 #include <linux/mod_devicetable.h>
 #include <linux/of_platform.h>
@@ -108,7 +109,8 @@  int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input)
 {
 	unsigned long flags;
 	u8 mcn_shift = 0, dev_shift = 0;
-	u32 ret;
+	u32 val;
+	int ret;
 
 	spin_lock_irqsave(&qe_lock, flags);
 	if (cmd == QE_RESET) {
@@ -135,13 +137,12 @@  int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input)
 	}
 
 	/* wait for the QE_CR_FLG to clear */
-	ret = spin_event_timeout((ioread32be(&qe_immr->cp.cecr) & QE_CR_FLG) == 0,
-				 100, 0);
-	/* On timeout (e.g. failure), the expression will be false (ret == 0),
-	   otherwise it will be true (ret == 1). */
+	ret = readx_poll_timeout_atomic(ioread32be, &qe_immr->cp.cecr, val, (val & QE_CR_FLG) == 0,
+					0, 100);
+	/* On timeout, ret is -ETIMEDOUT, otherwise it will be 0. */
 	spin_unlock_irqrestore(&qe_lock, flags);
 
-	return ret == 1;
+	return ret == 0;
 }
 EXPORT_SYMBOL(qe_issue_cmd);