2022-01-07 09:05:11

by Wayne Chang

[permalink] [raw]
Subject: [PATCH 1/1] usb: gadget: tegra-xudc: Do not program SPARAM

According to the Tegra Technical Reference Manual, SPARAM
is a read-only register and should not be programmed in
the driver.

The change removes the wrong SPARAM usage.

Signed-off-by: Wayne Chang <[email protected]>
---
drivers/usb/gadget/udc/tegra-xudc.c | 8 --------
1 file changed, 8 deletions(-)

diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c
index 43f1b0d461c1..716d9ab2d2ff 100644
--- a/drivers/usb/gadget/udc/tegra-xudc.c
+++ b/drivers/usb/gadget/udc/tegra-xudc.c
@@ -32,9 +32,6 @@
#include <linux/workqueue.h>

/* XUSB_DEV registers */
-#define SPARAM 0x000
-#define SPARAM_ERSTMAX_MASK GENMASK(20, 16)
-#define SPARAM_ERSTMAX(x) (((x) << 16) & SPARAM_ERSTMAX_MASK)
#define DB 0x004
#define DB_TARGET_MASK GENMASK(15, 8)
#define DB_TARGET(x) (((x) << 8) & DB_TARGET_MASK)
@@ -3295,11 +3292,6 @@ static void tegra_xudc_init_event_ring(struct tegra_xudc *xudc)
unsigned int i;
u32 val;

- val = xudc_readl(xudc, SPARAM);
- val &= ~(SPARAM_ERSTMAX_MASK);
- val |= SPARAM_ERSTMAX(XUDC_NR_EVENT_RINGS);
- xudc_writel(xudc, val, SPARAM);
-
for (i = 0; i < ARRAY_SIZE(xudc->event_ring); i++) {
memset(xudc->event_ring[i], 0, XUDC_EVENT_RING_SIZE *
sizeof(*xudc->event_ring[i]));
--
2.25.1



2022-02-25 14:10:42

by Thierry Reding

[permalink] [raw]
Subject: Re: [PATCH 1/1] usb: gadget: tegra-xudc: Do not program SPARAM

On Fri, Jan 07, 2022 at 05:04:43PM +0800, Wayne Chang wrote:
> According to the Tegra Technical Reference Manual, SPARAM
> is a read-only register and should not be programmed in
> the driver.
>
> The change removes the wrong SPARAM usage.
>
> Signed-off-by: Wayne Chang <[email protected]>
> ---
> drivers/usb/gadget/udc/tegra-xudc.c | 8 --------
> 1 file changed, 8 deletions(-)

What's the impact on this? Does it fix a bug? Or is it more of a
cosmetic change?

Thierry


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