Hi Greg,
On Thu, 2 Oct 2025 17:43:52 +0200 Greg KH gregkh@linuxfoundation.org wrote:
On Thu, Oct 02, 2025 at 10:57:24AM -0400, Hugo Villeneuve wrote:
From: Hugo Villeneuve hvilleneuve@dimonoff.com
Commit 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed") permanently enabled access to the enhanced features in sc16is7xx_probe(), and it is never disabled after that.
Therefore, remove useless re-enable of enhanced features in sc16is7xx_set_baud().
Fixes: 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com
drivers/tty/serial/sc16is7xx.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 1a2c4c14f6aac..c7435595dce13 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -588,13 +588,6 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) div /= prescaler; }
- /* Enable enhanced features */
- sc16is7xx_efr_lock(port);
- sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
SC16IS7XX_EFR_ENABLE_BIT,SC16IS7XX_EFR_ENABLE_BIT);- sc16is7xx_efr_unlock(port);
- /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT,
-- 2.39.5
Why is this needed for stable kernels? It's useless, what is it harming?
It is useless, and doing no "harm", but since the device is on a SPI or I2C bus, this is inefficient as it takes precious cycles on these busses.
If so, please send it separately, not as a part of a larger series.
That is why this patch is the first in the series, so that it could be easily backported. But I can send it separately, sure.
Hugo.