[PATCH] staging: panel: fix lcd type

[PATCH] staging: panel: fix lcd type

[Sudip Mukherjee]

the lcd type as defined in the Kconfig is not matching in the code.
as a result the rs, rw and en pins were getting interchanged.
Kconfig defines the value of PANEL_LCD to be 1 if we select custom
configuration but in the code LCD_TYPE_CUSTOM is defined as 5.

my hardware is LCD_TYPE_CUSTOM, but the pins were assigned to it
as pins of LCD_TYPE_OLD, and it was not working.
Now values are corrected with referenece to the values defined in
Kconfig and it is working.
checked on JHD204A lcd with LCD_TYPE_CUSTOM configuration.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---

I traced the code till 2.6.32.2 and it was same problem in lcd_init(),
it can work only if we have configured for custom lcd type with
connections similar to the connections of LCD_TYPE_OLD.

 drivers/staging/panel/panel.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index 16fee49..4ffff2e 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -314,11 +314,11 @@ static unsigned char lcd_bits[LCD_PORTS][LCD_BITS][BIT_STATES];
  * LCD types
  */
 #define LCD_TYPE_NONE		0
-#define LCD_TYPE_OLD		1
-#define LCD_TYPE_KS0074		2
-#define LCD_TYPE_HANTRONIX	3
-#define LCD_TYPE_NEXCOM		4
-#define LCD_TYPE_CUSTOM		5
+#define LCD_TYPE_CUSTOM		1
+#define LCD_TYPE_OLD		2
+#define LCD_TYPE_KS0074		3
+#define LCD_TYPE_HANTRONIX	4
+#define LCD_TYPE_NEXCOM		5
 
 /*
  * keypad types
-- 
1.8.1.2

Re: [PATCH] staging: panel: fix lcd type

[Willy Tarreau]

Hi Sudip!

On Tue, Mar 24, 2015 at 10:18:10AM +0530, Sudip Mukherjee wrote:
> the lcd type as defined in the Kconfig is not matching in the code.
> as a result the rs, rw and en pins were getting interchanged.
> Kconfig defines the value of PANEL_LCD to be 1 if we select custom
> configuration but in the code LCD_TYPE_CUSTOM is defined as 5.
> 
> my hardware is LCD_TYPE_CUSTOM, but the pins were assigned to it
> as pins of LCD_TYPE_OLD, and it was not working.
> Now values are corrected with referenece to the values defined in
> Kconfig and it is working.
> checked on JHD204A lcd with LCD_TYPE_CUSTOM configuration.
> 
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>

OK but you also need to hange the MODULE_PARM_DESC(lcd_type) to
match these new settings. Given that this is a bug, you can even
think about adding a Cc: stable tag.

Thanks,
Willy

Re: [PATCH] staging: panel: fix lcd type

[Sudip Mukherjee]

On Tue, Mar 24, 2015 at 08:04:11AM +0100, Willy Tarreau wrote:
> Hi Sudip!
> 
> On Tue, Mar 24, 2015 at 10:18:10AM +0530, Sudip Mukherjee wrote:
> > the lcd type as defined in the Kconfig is not matching in the code.
> > as a result the rs, rw and en pins were getting interchanged.
> > Kconfig defines the value of PANEL_LCD to be 1 if we select custom
> > configuration but in the code LCD_TYPE_CUSTOM is defined as 5.
> > 
> > my hardware is LCD_TYPE_CUSTOM, but the pins were assigned to it
> > as pins of LCD_TYPE_OLD, and it was not working.
> > Now values are corrected with referenece to the values defined in
> > Kconfig and it is working.
> > checked on JHD204A lcd with LCD_TYPE_CUSTOM configuration.
> > 
> > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> 
> OK but you also need to hange the MODULE_PARM_DESC(lcd_type) to
> match these new settings. Given that this is a bug, you can even
> think about adding a Cc: stable tag.
i missed seeing that MODULE_PARM_DESC. i wanted to have your
confirmation first before ccing stable.

will cc stable in v2.
but before that i think i need to read the Documentation about how to
cc stable for those many stable versions till 2.6.32

regards
sudip

> 
> Thanks,
> Willy
> 

Re: [PATCH] staging: panel: fix lcd type

[Willy Tarreau]

On Tue, Mar 24, 2015 at 01:22:16PM +0530, Sudip Mukherjee wrote:
> On Tue, Mar 24, 2015 at 08:04:11AM +0100, Willy Tarreau wrote:
> > Hi Sudip!
> > 
> > On Tue, Mar 24, 2015 at 10:18:10AM +0530, Sudip Mukherjee wrote:
> > > the lcd type as defined in the Kconfig is not matching in the code.
> > > as a result the rs, rw and en pins were getting interchanged.
> > > Kconfig defines the value of PANEL_LCD to be 1 if we select custom
> > > configuration but in the code LCD_TYPE_CUSTOM is defined as 5.
> > > 
> > > my hardware is LCD_TYPE_CUSTOM, but the pins were assigned to it
> > > as pins of LCD_TYPE_OLD, and it was not working.
> > > Now values are corrected with referenece to the values defined in
> > > Kconfig and it is working.
> > > checked on JHD204A lcd with LCD_TYPE_CUSTOM configuration.
> > > 
> > > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> > 
> > OK but you also need to hange the MODULE_PARM_DESC(lcd_type) to
> > match these new settings. Given that this is a bug, you can even
> > think about adding a Cc: stable tag.
> i missed seeing that MODULE_PARM_DESC. i wanted to have your
> confirmation first before ccing stable.
> 
> will cc stable in v2.
> but before that i think i need to read the Documentation about how to
> cc stable for those many stable versions till 2.6.32

Just put this before your signed-off-by at the bottom fo the commit message :

  Cc: <stable@vger.kernel.org> # 2.6.32+

Willy