WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

[gregkh]

The patch below was submitted to be applied to the 5.4-stable tree.

I fail to see how this patch meets the stable kernel rules as found at
Documentation/process/stable-kernel-rules.rst.

I could be totally wrong, and if so, please respond to 
<stable@vger.kernel.org> and let me know why this patch should be
applied.  Otherwise, it is now dropped from my patch queues, never to be
seen again.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9b8d7072d6552ee5c57e5765f211f267041f9557 Mon Sep 17 00:00:00 2001
From: "H. Nikolaus Schaller" <hns@goldelico.com>
Date: Thu, 7 Nov 2019 11:30:35 +0100
Subject: [PATCH] net: wireless: ti: wl1251 add device tree support

We will have the wl1251 defined as a child node of the mmc interface
and can read setup for gpios, interrupts and the ti,use-eeprom
property from there instead of pdata to be provided by pdata-quirks.

Fixes: 81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Cc: <stable@vger.kernel.org> # v4.7+
[Ulf: Fixed up some complaints from checkpatch]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/net/wireless/ti/wl1251/sdio.c b/drivers/net/wireless/ti/wl1251/sdio.c
index 677f1146ccf0..f1224b948f83 100644
--- a/drivers/net/wireless/ti/wl1251/sdio.c
+++ b/drivers/net/wireless/ti/wl1251/sdio.c
@@ -16,6 +16,9 @@
 #include <linux/irq.h>
 #include <linux/pm_runtime.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/of_irq.h>
 
 #include "wl1251.h"
 
@@ -217,6 +220,7 @@ static int wl1251_sdio_probe(struct sdio_func *func,
 	struct ieee80211_hw *hw;
 	struct wl1251_sdio *wl_sdio;
 	const struct wl1251_platform_data *wl1251_board_data;
+	struct device_node *np = func->dev.of_node;
 
 	hw = wl1251_alloc_hw();
 	if (IS_ERR(hw))
@@ -248,6 +252,17 @@ static int wl1251_sdio_probe(struct sdio_func *func,
 		wl->power_gpio = wl1251_board_data->power_gpio;
 		wl->irq = wl1251_board_data->irq;
 		wl->use_eeprom = wl1251_board_data->use_eeprom;
+	} else if (np) {
+		wl->use_eeprom = of_property_read_bool(np,
+						       "ti,wl1251-has-eeprom");
+		wl->power_gpio = of_get_named_gpio(np, "ti,power-gpio", 0);
+		wl->irq = of_irq_get(np, 0);
+
+		if (wl->power_gpio == -EPROBE_DEFER ||
+		    wl->irq == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto disable;
+		}
 	}
 
 	if (gpio_is_valid(wl->power_gpio)) {

Re: WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

[H. Nikolaus Schaller]

Hi Greg,
I have checked with Documentation/process/stable-kernel-rules.rst but not found out
what is failing.

Basically this belongs to a series to fix a bug

81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")

that exists since v4.7 and has been hidden by patches which came into the kernel over
the time.

BR and thanks,
Nikolaus Schaller

> Am 11.12.2019 um 15:06 schrieb <gregkh@linuxfoundation.org> <gregkh@linuxfoundation.org>:
> 
> The patch below was submitted to be applied to the 5.4-stable tree.
> 
> I fail to see how this patch meets the stable kernel rules as found at
> Documentation/process/stable-kernel-rules.rst.
> 
> I could be totally wrong, and if so, please respond to 
> <stable@vger.kernel.org> and let me know why this patch should be
> applied.  Otherwise, it is now dropped from my patch queues, never to be
> seen again.
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From 9b8d7072d6552ee5c57e5765f211f267041f9557 Mon Sep 17 00:00:00 2001
> From: "H. Nikolaus Schaller" <hns@goldelico.com>
> Date: Thu, 7 Nov 2019 11:30:35 +0100
> Subject: [PATCH] net: wireless: ti: wl1251 add device tree support
> 
> We will have the wl1251 defined as a child node of the mmc interface
> and can read setup for gpios, interrupts and the ti,use-eeprom
> property from there instead of pdata to be provided by pdata-quirks.
> 
> Fixes: 81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
> Acked-by: Kalle Valo <kvalo@codeaurora.org>
> Cc: <stable@vger.kernel.org> # v4.7+
> [Ulf: Fixed up some complaints from checkpatch]
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> 
> diff --git a/drivers/net/wireless/ti/wl1251/sdio.c b/drivers/net/wireless/ti/wl1251/sdio.c
> index 677f1146ccf0..f1224b948f83 100644
> --- a/drivers/net/wireless/ti/wl1251/sdio.c
> +++ b/drivers/net/wireless/ti/wl1251/sdio.c
> @@ -16,6 +16,9 @@
> #include <linux/irq.h>
> #include <linux/pm_runtime.h>
> #include <linux/gpio.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_irq.h>
> 
> #include "wl1251.h"
> 
> @@ -217,6 +220,7 @@ static int wl1251_sdio_probe(struct sdio_func *func,
> 	struct ieee80211_hw *hw;
> 	struct wl1251_sdio *wl_sdio;
> 	const struct wl1251_platform_data *wl1251_board_data;
> +	struct device_node *np = func->dev.of_node;
> 
> 	hw = wl1251_alloc_hw();
> 	if (IS_ERR(hw))
> @@ -248,6 +252,17 @@ static int wl1251_sdio_probe(struct sdio_func *func,
> 		wl->power_gpio = wl1251_board_data->power_gpio;
> 		wl->irq = wl1251_board_data->irq;
> 		wl->use_eeprom = wl1251_board_data->use_eeprom;
> +	} else if (np) {
> +		wl->use_eeprom = of_property_read_bool(np,
> +						       "ti,wl1251-has-eeprom");
> +		wl->power_gpio = of_get_named_gpio(np, "ti,power-gpio", 0);
> +		wl->irq = of_irq_get(np, 0);
> +
> +		if (wl->power_gpio == -EPROBE_DEFER ||
> +		    wl->irq == -EPROBE_DEFER) {
> +			ret = -EPROBE_DEFER;
> +			goto disable;
> +		}
> 	}
> 
> 	if (gpio_is_valid(wl->power_gpio)) {
> 

Re: WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

[Greg KH]

On Wed, Dec 11, 2019 at 03:19:19PM +0100, H. Nikolaus Schaller wrote:
> Hi Greg,
> I have checked with Documentation/process/stable-kernel-rules.rst but not found out
> what is failing.
> 
> Basically this belongs to a series to fix a bug
> 
> 81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
> 
> that exists since v4.7 and has been hidden by patches which came into the kernel over
> the time.

I do not understand at all.

What does tagging all of these random wifi driver commits with cc:
stable have to do with an old mmc commit from 4.7-rc1?

confused,

greg k-h

Re: WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

[H. Nikolaus Schaller]

> Am 11.12.2019 um 15:24 schrieb Greg KH <gregkh@linuxfoundation.org>:
> 
> On Wed, Dec 11, 2019 at 03:19:19PM +0100, H. Nikolaus Schaller wrote:
>> Hi Greg,
>> I have checked with Documentation/process/stable-kernel-rules.rst but not found out
>> what is failing.
>> 
>> Basically this belongs to a series to fix a bug
>> 
>> 81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
>> 
>> that exists since v4.7 and has been hidden by patches which came into the kernel over
>> the time.
> 
> I do not understand at all.
> 
> What does tagging all of these random wifi driver commits with cc:
> stable have to do with an old mmc commit from 4.7-rc1?

v4.7 received the commit ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel").

This commit itself is not bad but has a bad side-effect that it breaks the device tree
and platform quirks of the wl1251 connected to mmc3 port of the OpenPandora.

The reason turned out to be because it now requires a device tree record for the mmc port
while the v4.7 status was to have a mmc port created by a platform quirk - without scanning
the DT.

To be able to fix that we have to
* modify the device tree
* remove the platform quirk for pandora and replace by DT based instantiation of the mmc port
* make sure that what the platform quirk does is still done in the mmc subsystem
* fix some assumptions introduced by later patches which make the device non-detectable

The only alternative I can imagine would be to revert "mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel".

This would fix WiFi for OpenPandora. But - besides you can't simply git revert any more - it
would require fixing much more subsystems than omap_hsmmc + mmc + wl1251 + Pandora device tree.

Yes, it is unfortunate that nobody did care about this bug (although known) before I
recently did a git bisect to identify this commit. So it got buried under a thick layer
of kernel patches so that getting back a working solution touches areas outside the omap_hsmmc
driver.

Does this better explain what the rationale is?

BR and thanks,
Nikolaus Schaller

Re: WTF: patch "[PATCH] net: wireless: ti: wl1251 add device tree support" was seriously submitted to be applied to the 5.4-stable tree?

[H. Nikolaus Schaller]

> Am 11.12.2019 um 15:24 schrieb Greg KH <gregkh@linuxfoundation.org>:
> 
> On Wed, Dec 11, 2019 at 03:19:19PM +0100, H. Nikolaus Schaller wrote:
>> Hi Greg,
>> I have checked with Documentation/process/stable-kernel-rules.rst but not found out
>> what is failing.
>> 
>> Basically this belongs to a series to fix a bug
>> 
>> 81eef6ca9201 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
>> 
>> that exists since v4.7 and has been hidden by patches which came into the kernel over
>> the time.
> 
> I do not understand at all.
> 
> What does tagging all of these random wifi driver commits with cc:
> stable have to do with an old mmc commit from 4.7-rc1?

Here is also the cover letter for the series when they were originally submitted to fix linux-next:

https://lore.kernel.org/patchwork/cover/1142016/

Unfortunately that gets lost by the transition to stable.

BR,
Nikolaus Schaller