* [PATCH] staging: fbtft: Changed calls to udelays() functions for usleep_range()
@ 2024-09-22 12:12 Fabio
2024-09-22 21:59 ` Nam Cao
0 siblings, 1 reply; 2+ messages in thread
From: Fabio @ 2024-09-22 12:12 UTC (permalink / raw)
To: dri-devel, linux-fbdev, linux-staging, linux-kernel, gregkh
Replaced two lines of calling udelays by usleep_range() functions, adding
more efficiency due to the need of long-lasting delays of more than 10us.
Signed-off-by: Fabio Bareiro <joakobar2000@gmail.com>
---
drivers/staging/fbtft/fb_ra8875.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/fbtft/fb_ra8875.c b/drivers/staging/fbtft/fb_ra8875.c
index 0ab1de6647d0..edd467c6bf1a 100644
--- a/drivers/staging/fbtft/fb_ra8875.c
+++ b/drivers/staging/fbtft/fb_ra8875.c
@@ -210,7 +210,7 @@ static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
}
len--;
- udelay(100);
+ usleep_range(100, 150);
if (len) {
buf = (u8 *)par->buf;
@@ -231,7 +231,7 @@ static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
/* restore user spi-speed */
par->fbtftops.write = fbtft_write_spi;
- udelay(100);
+ usleep_range(100, 150);
}
static int write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] staging: fbtft: Changed calls to udelays() functions for usleep_range()
2024-09-22 12:12 [PATCH] staging: fbtft: Changed calls to udelays() functions for usleep_range() Fabio
@ 2024-09-22 21:59 ` Nam Cao
0 siblings, 0 replies; 2+ messages in thread
From: Nam Cao @ 2024-09-22 21:59 UTC (permalink / raw)
To: Fabio; +Cc: dri-devel, linux-fbdev, linux-staging, linux-kernel, gregkh
On Sun, Sep 22, 2024 at 09:12:13AM -0300, Fabio wrote:
> Replaced two lines of calling udelays by usleep_range() functions, adding
> more efficiency due to the need of long-lasting delays of more than 10us.
>
> Signed-off-by: Fabio Bareiro <joakobar2000@gmail.com>
> ---
> drivers/staging/fbtft/fb_ra8875.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/fbtft/fb_ra8875.c b/drivers/staging/fbtft/fb_ra8875.c
> index 0ab1de6647d0..edd467c6bf1a 100644
> --- a/drivers/staging/fbtft/fb_ra8875.c
> +++ b/drivers/staging/fbtft/fb_ra8875.c
> @@ -210,7 +210,7 @@ static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
> }
> len--;
>
> - udelay(100);
> + usleep_range(100, 150);
>
> if (len) {
> buf = (u8 *)par->buf;
> @@ -231,7 +231,7 @@ static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
>
> /* restore user spi-speed */
> par->fbtftops.write = fbtft_write_spi;
> - udelay(100);
> + usleep_range(100, 150);
> }
Are you sure that these changes are safe to make? If this write_reg8_bus8()
function is ever called in atomic context, this patch would break the
driver.
Unless it can be verified with hardware, I wouldn't make this kind of
changes.
Best regards,
Nam
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-09-22 21:59 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-09-22 12:12 [PATCH] staging: fbtft: Changed calls to udelays() functions for usleep_range() Fabio
2024-09-22 21:59 ` Nam Cao
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).